Skip to main content
Journal of Experimental Orthopaedics logoLink to Journal of Experimental Orthopaedics
. 2022 Jan 20;9:12. doi: 10.1186/s40634-021-00443-x

Common peroneal nerve palsy after TKA in valgus deformities; a systematic review

Raymond Puijk 1,, Rachid Rassir 1, Laura M Kok 1, Inger N Sierevelt 1,2, Peter A Nolte 1
PMCID: PMC8776926  PMID: 35059901

Abstract

Purpose

The aim of this systematic review is to investigate the prevalence of Common Peroneal Nerve Palsy after total knee arthroplasty in valgus deformities. Furthermore, the effectiveness of a peroneal nerve release prior to arthroplasty to prevent the palsy will be investigated.

Methods

PubMed and Google Scholar were searched. Search terms regarding valgus deformity and total knee arthroplasty were used. Data analysis and extraction were performed using the web application ‘Rayyan QCRI’ according to PRISMA guidelines and screened according to the inclusion and exclusion criteria.

Results

Twenty-seven studies were included, representing 1397 valgus knees. Knee balancing was performed in 19 studies with lateral soft tissue releases (1164 knees) and 8 studies (233 knees) with an additional osteotomy. Two studies (41 knees) in the lateral soft tissue release group conducted a peroneal nerve release simultaneous to arthroplasty. Common peroneal nerve palsies occurred in 26 cases (1.9%). Overall, no significant difference in palsy ratio between studies was found by using a peroneal nerve release (p = 0.90), between lateral soft tissue releases and osteotomies (p = 0.11) or between releases of specific ligaments.

Conclusion

Common peroneal nerve palsies occur in 1.9% of the cases after total knee arthroplasty in valgus deformities. No difference in the number of palsies was seen when using a peroneal nerve release or using different balancing techniques. However, literature about peroneal nerve releases was very limited, therefore, the effectiveness of a peroneal nerve release remains unclear.

Level of evidence

LEVEL III: Systematic review.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-021-00443-x.

Keywords: Valgus deformity, Total knee arthroplasty, Soft tissue release, Peroneal nerve release, Common peroneal nerve palsy

Introduction

Common peroneal nerve palsy (CPNP) is a feared complication after total knee arthroplasty (TKA). Previous studies show valgus deformity and flexion contracture as predisposing factors to develop CPNP [15]. An increased anatomical femorotibial angle (aFTA) of > 10° is commonly used to define a valgus knee [68]. In the literature, the reported CPNP incidence after TKA in valgus deformities with an aFTA > 10° (TKA-V) ranges between 0.3–9.5% [3, 917]. Injury of the common peroneal nerve (CPN) can be caused by indirect damage due to stretch or ischaemia after correction, or by direct injury due to laceration of the CPN during lateral soft tissue release (STR) [8, 11, 12, 1820]. Commonly contracted and released ligaments in valgus knees include the iliotibial band (ITB), posterolateral capsule (PLC), lateral collateral ligament (LCL), popliteus tendon (POP) and lateral gastrocnemius tendon [8, 21]. The selection of ligaments to be released depend mainly on the tightness of the ligaments in extension and/or flexion. Ligaments can be released through pie-crusting [7, 13, 20, 2225], a subperiosteal release [13, 23, 2628] or in a transverse manner. Also, shifting the insertion of a ligament by use of an osteotomy (OT), like a lateral femoral epicondyle osteotomy (LFEO) [2937] or medial femoral epicondyle osteotomy (MFEO) [30, 33] is used. However, an overzealous release may result in direct injury of the CPN, late-onset instability and even a higher revision rate [33, 38, 39].

Recovery from CPNP usually take place within a year; however, residual damage is certainly not uncommon [1, 4, 5, 12]. As CPNP has serious consequences, orthopaedic surgeons aim to prevent this complication by a concomitant peroneal nerve release (PNR) [8, 40]. A PNR is a procedure performed simultaneously to TKA-V, which explores the nerve and removes the constricted dressings to release the CPN. Therefore, it yields the nerve to have more capacity to extend and protects it against mechanical stretching after balancing the knee properly during TKA-V. Due to the limited number of studies investigating PNR, no consensus has yet been reached on the value and indication of the procedure.

This systematic review primarily attempts to investigate the CPNP incidence after TKA-V and the rate will be compared between different valgus correcting techniques, including lateral STR and OT. Secondarily, the effectiveness of a PNR in preventing CPNP after TKA-V will be investigated.

Material and methods

Search strategy

A librarian-assisted comprehensive search of the literature was performed in October 2020 in PubMed and Google Scholar. The primary search was mainly focused on the surgical treatment and outcome of TKA-V. Search terms and associated synonyms that were included in the search are displayed in Table 1. A total of 3.945 articles were identified through PubMed and Google Scholar (Fig. 1 [Additional file 1]). The analysis was done according to the ‘Preferred Reporting Items of Systematic review and Meta-analyses’ (PRISMA) [41]. Through the web application ‘Rayyan QCRI’ [42], duplicates were removed and the remaining articles were screened for eligibility, according to the screening criteria (Table 2). The screening was independently done by three reviewers (X, X and X), a fourth reviewer (X) was consulted in case of doubt about the suitability of an article [43]. To ensure no relevant articles were omitted, a cross-reference check was performed on the included articles. A consensus was achieved on all included articles based on inclusion and exclusion criteria.

Table 1.

PubMed search strategy, October 2020

(((((((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR ((“total”[All Fields] AND “knee”[All Fields]) AND “arthroplasty”[All Fields])) OR “total knee arthroplasty”[All Fields]) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR ((“total”[All Fields] AND “knee”[All Fields]) AND “replacement”[All Fields])) OR “total knee replacement”[All Fields])) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR (“knee”[All Fields] AND “arthroplasty”[All Fields])) OR “knee arthroplasty”[All Fields])) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) “knee replacement arthroplasty”[All Fields]) OR (“knee”[All Fields] AND “replacement”[All Fields])) OR “knee replacement”[All Fields])) OR (“TKA”[Title/Abstract] OR “TKR”[Title/Abstract])) ((((((“genu valgum”[MeSH Terms] OR (“genu”[All Fields] AND “valgum”[All Fields])) OR “genu valgum”[All Fields]) OR (“genu”[All Fields] AND “valga”[All Fields])) OR “genu valga”[All Fields]) OR ((((“genu valgum”[MeSH Terms] OR (“genu”[All Fields] AND “valgum”[All Fields])) OR “genu valgum”[All Fields]) OR (“knock”[All Fields] AND “knee”[All Fields])) OR “knock knee”[All Fields])) OR “knock knees”[Title/Abstract])) (((((((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR ((“total”[All Fields] AND “knee”[All Fields]) AND “arthroplasty”[All Fields])) OR “total knee arthroplasty”[All Fields]) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR ((“total”[All Fields] AND “knee”[All Fields]) AND “replacement”[All Fields])) OR “total knee replacement”[All Fields])) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR (“knee”[All Fields] AND “arthroplasty”[All Fields])) OR “knee arthroplasty”[All Fields])) OR ((((“arthroplasty, replacement, knee”[MeSH Terms] OR ((“arthroplasty”[All Fields] AND “replacement”[All Fields]) AND “knee”[All Fields])) OR “knee replacement arthroplasty”[All Fields]) OR (“knee”[All Fields] AND “replacement”[All Fields])) OR “knee replacement”[All Fields])) OR (“TKA”[Title/Abstract] OR

“TKR”[Title/Abstract])) AND “valgus”[All Fields] OR “Joint Deformities, Acquired”[Mesh])

Table 2.

Inclusion and exclusion criteria

Inclusion
 1 Valgus deformities > 10 degrees
 2 Intervention: Primary total knee arthroplasty
 3 Intervention: peroneal nerve release
 4 Articles reporting soft tissue release procedures and pre-and postoperative clinical outcomes (e.g., measurements of alignments and common peroneal nerve palsy)
 5 Prospective or retrospective study design.
 6 Articles written in English or Dutch.
Exclusion
 1 Valgus deformities < 10 degrees
 2 Genu varus, recurvatum, neutral or mixed alignment populations
 3 Previous knee surgery, unicompartimental knee arthroplasties or revisions
 4 Double publication of the same cohort
 5 Systematic reviews, cadaver studies, case reports or studies < 1980

Data extraction

Data were extracted from each study by the first author (X) and collected in Microsoft Excel 2020 (Microsoft Corp., Redmond, WA, USA). Data of each article that was collected, included first author, study design (pro- or retrospective), study characteristics (year of publication, country, number of knees and patients), patient characteristics (age, gender, body mass index [12], the ratio of osteoarthritis (OA) or rheumatoid arthritis and follow-up), inclusion and exclusion criteria, alignment details (classification type, pre-and postoperative mechanical axis, anatomical axis (aFTA), range of motion and flexion contracture angle), peroneal nerve release, arthroplasty (surgical approach, implant design), lateral soft tissue release (technique, sequence and affected ligaments), osteotomies, common peroneal nerve palsy (duration, preoperative valgus alignment), other complications (residual valgus alignment). In case of unavailable or unspecified information, the authors were contacted and asked to provide the missing information.

Methodological quality assessment

The quality of the non-randomized studies was assessed by the first author (X), utilizing the Methodological Index for Non-Randomized Studies (MINORS) [44]. In case of any doubt, the second reviewer (X) was consulted to determine the quality of the study. The outcome of the index per study is stated in Table 3.

Table 3.

Study characteristics

Study and year Country Study design Patients (knees) Gender, female (%) Age in yearsa (mean ± SD) Patients with OA (%) Preop. aFTAa (mean ± SD) Postop. aFTAa (mean ± SD) preop. FCa (mean ± SD) CPNP, cases (%) Soft tissue release in sequence of structures (% of knees) Follow-up years (mean ± SDa) MINOR score
No peroneal nerve release – with soft tissue release
 Greenberg et al. 2020 USA Retr 95 (104) 73 ± 8 n/a 16.2 ± 5.6 5.4 ± 2.8 3.0 ± 6.5 3 (2.9%)

1) ITB subperiosteal (100%)

2) PLC transverse (n/a) 3) POP transverse (n/a)

1.8 ± 1.3 17/24
 Li et al. 2020 China Pros 30 (35) 28 (93) 64.8 ± 8 30 (100%) 20.39 ± 7.79 7.0 ± 2.3 6.4 ± 9.0 1 (2.9%) 1) ITB pie-crusting (100%) 2) LCL transverse (100%) 3) POP transverse (n/a) 4) PLC (n/a) 3.9 ± 2.4 10/16
 Ren et al. 2020 China Retr 58 (61) 47 (81) 65 ± 8 49 (84%) 30.6 ± 6.3 7.3 ± 2.2 0 ± 0 4 (6.6%) 1) ITB (100%) 2) LCL transverse (100%) 3) POP transverse (3.2%) 10.5 ± 2.4 10/16
 Cheng et al. 2020 China Retr 56 (56) 31 (55) 62 ± 3.7 22 (39%) 21.4 ± 5.4 2.6 ± n/a n/a 0 (0%) 1) ITB subperiosteal (100%) 2) LCL pie-crusting (8.9%) 3) PCL pie-crusting (8.9%) 1 ± 0 10/16
 Matar et al. 2019 UK Retr 104 (110) 87 (84) 68.7 ± 9.2 85 (82%) 18.6 ± 7.5 3.8 ± 2.0 n/a 0 (0%) 1) ITB subperiosteal (100%) 2) POP (28.3%) 5.5 ± 2.4 11/16
 Guo et al. 2018 China Retr 31 (31) 29 (94) 66.5 ± n/a 31 (100%) 21.7 ± 4.6 7.7 ± 1.7 n/a 0 (0%) Release of the ITB (100%), PLC (100%), LCL (100%) 0.8 ± 0.1 16/24
 Jaju et al. 2018 India Pros 32 (32) 22 (69) 62.7 ± 6.9 9 (28%) 18.59 ± 8.32 3.7 ± 0.9 8.25 ± 4.38 0 (0%) 1) PLC transverse (100%) 2) ITB pie-crusting (47%) 1.9 ± 0.7 11/16
 Boettner et al. 2016 USA Retr 164 (181) 130 (79) 67 ± 9.3 164 (100%) 14.2 ± 4.9 5.2 ± 2.8 4.8 ± 7.3 1 (0.6%) 1) ITB transverse (100%), PLC transverse (100%) and LCL transverse (100%) 2.0 ± 1.0 12/16
 Zhou et al. 2014 China Retr 32 (37) 20 (63) 57.2 ± 6.1 22 (69%) 32.72 ± 9.68 4.89 ± 0.9 −0.78 ± 2.49 3 (8.1%) 1) PLC pie-crusting (100%) 2) LCL pie-crusting (100%) 3) POP transverse (24%) 10 ± 0.7 11/16
 Satish et al. 2013 India Pros 27 (32) 17 (63) 54 ± 5.4 10 (37%) 25.4 ± 12 4 ± 2.5 n/a 2 (6.3%)

1) ITB subperiosteal (100%)

2) PLC transverse (59.3%)

3) POP (21.8%) + LCL (21.8%)

5.0 ± 1.2 12/16
 Chechik et al. 2012 Israel Retr 42 (51) 38 (91) 72.7 ± 8.3 31 (74%) 17.5 ± 4.6 6.3 ± 2.2 [−1] ± 3 1 (2.0%) 1) Transverse release of the PLC (100%) 3.5 ± 1.9 10/16
 koskinen et al. 2011 Finland Retr 48 (52) 46 (96) 66 ± 11.1 37 (77%) 23 ± 8.0 7 ± 5.6 9 ± 5.6 (in 25 knees) 1 (1.9%)

1) ITB pie-crusting (61.5%)

2) POP (40.4%) 3) LCL (18.6%) 4) PLC (5.8%)

9.0 ± 3.6 11/16
 Rajgopal et al. 2011 India Retr 53 (78) 34 (64) 74 ± 10 16 (30%) 20.0 ± 7.2 5.0 ± 0.8 N/A 2 (2.6%)

1) ITB pie-crusting (100%)

2) POP pie-crusting (2.6%)

10.0 ± 1.2 9/16
 Apostolo-poulos et al. 2010 Greece Pros 24 (24) 7 (29) 72 ± 5.6 17 (71%) 23 ± 4.9 5.5 ± 1.3 11 ± 4.3 (in 9 knees) 0 (0.0%)

1) ITB subperiosteal (100%)

2) LCL and POP subperiosteal (100%) 3) PLC (37.5%)

11.5 ± 1.8 11/16
 Boyer P et al. 2008 France Retr 63 (63) 56 (89) 56.9 ± 11.9 43 (68%) 14.7 ± 3.7 1.0 ± 0.4 n/a 1 (1.6%)

1) ITB subperiosteal (100%)

2) LCL and POP subperiosteal (7.9%) 3) PLC (6.3%)

7.0 ± 1.5 10/16
 Elkus et al. 2004 USA Pros 35 (42) 27 (77) 67 ± 12.7 28 (80%) 15.0 ± 5.1 5.0 ± 2.3 7.0 ± n/a 0 (0.0%)

1) PLC + LCL and POP transverse (100%)

2) ITB pie-crusting (100%)

9.0 ± 2.1 13/16
 Stern et al. 1991 USA Retr 98 (134) 83 (85) 68 ± 8.8 88 (90%) 19.0 ± 8.4 7.0 ± 3.4 n/a 5 (3.7%) 1) PLC with LCL and POP transverse (100%) 2) ITB (n/a) 4.5 ± 1.5 11/16
Peroneal nerve release – with soft tissue release
 Xu J et al. 2020 China Pros 30 (34) 21 (70) 70.2 ± 9.3 10 (33%) 31.3 ± 8.0 4.9 ± 2.0 n/a 0 (0%) 1) ITB pie-crusting (100%) 2) PLC pie-crusting (100%) 3) LCL and POP (n/a) 2.25 ± 0.4 12/16
 Cree et al. 1999 Australia Retr 7 (7) 72 ± n/a 6 (86%) 24.0 ± 7.4 6.0 ± 2.2 n/a 1 (14.2%) Not noted 0.6 ± 0.4 9/16
 Study Country Study design Patients (knees) Gender, female (%) Age in yearsa (mean ± SD) Patients with OA (%) Preop. aFTAa (mean ± SD) Postop. aFTAa (mean ± SD) preop FCa (mean ± SD) CPNP cases (%) Soft tissue release in sequence of structures (%) Osteo-tomy (% of knees) Follow-up years (mean ± SDa) MINOR score
No peroneal nerve release – with osteotomies and soft tissue release
 Raut et al. 2020 UK Retr 23 (25) 15 (65) 68 ± 11.4 14 (61%) 20 ± 4.3 4 ± 1.3 n/a 0 (0%)

1) ITB subperiosteal (100%)

2) POP (100%)

LFEO (100%) 5 ± 3.8 10/16
 Mou et al. 2019 China RCT 25 (27) 63 ± 11 n/a 31.6 ± 8 7.0 ± 2.4 n/a 0 (0%) 1) ITB pie-crusting (100%) 2) PLC (n/a) MFEO (100%) 4.6 ± 0.9
 Cheng et al. 2019 China Pros 15 (16) 14 (93) 67.4 ± 6.2 n/a n/a n/a n/a 0 (0%) 1) ITB pie-crusting (100%) 2) PLC transverse (100%) MFEO (100%) 2.2 ± 0.7 12/16
 Scior et al. 2018 Germany Pros 98 (98) 71 (72) 71.6 ± 10.5 n/a 14.9 ± 2.7 6.4 ± 0.6 4 ± 3 0 (0%) 1) ITB subperiosteal (100%) 2) PLC transverse (100%) LFEO (100%) 4.5 ± 1 9/16
 Conjeski et al. 2018 USA Retr 10 (12) 7 (70) 68 ± 13.3 9 (90%) 16.4 ± 4.2 5.5 ± 0.9 n/a 1 (8.3%) No initial soft tissue release LFEO (100%) 2.9 ± 2.7 10/16
 Strauch et al. 2013 Germany Pros 27 (27) 69.5 ± 13.2 n/a 17.7 ± 5.0 7.2 ± 3.8 n/a 0 (0%) ITB transverse (100%) LFEO (100%) 1 ± n/a 9/16
 Hadjicostas et al. 2008 Germany Pros 15 (15) 73 ± 4.6 13 (87%) n/a n/a n/a 0 (0%) Partial release of the PLC (n/a) LFEO (100%) 2.3 ± 0.9 12/16
 Brilhault et al. 2002 France Pros 13 (13) 12 (92) 73 ± 3.6 12 (92%) n/a n/a n/a 0 (0%) ITB subperiosteal (100%) LFEO (100%) 4.7 ± 1.7 11/16

SD Standard deviation, OA Osteoarthritis, Preop Preoperative, Postop Postoperative, FC Flexion contracture, aFTA anatomical tibiofemoral angle, CPNP Common peroneal nerve palsy, MINOR Methodological Index for Non-Randomized Studies, LFEO Lateral femoral epicondyle osteotomy, MFEO Medial femoral epicondyle osteotomy

aMean ± SD is transformed if needed according to the statistical analysis section

Statistical analysis

Means and standard deviations were presented and calculated. Reported medians and ranges were transformed into weighted means and estimated standard deviation by the methods of Hozo et al. [45] and Walter et al. [46].

Heterogeneity was assessed using I2 and χ 2-tests, where an I2 of < 25% is considered low; 25–50% as moderate; > 50% as strong and > 75% as substantially heterogeneous by the methods Higgins et al. [24] In case of substantial heterogeneity between studies (I2 > 75%), a qualitative/narrative data extraction was performed [24]. As the heterogeneity of the CPNP incidence was not substantial among studies, data were pooled using a fixed-effect model and weighted on sample size. Because of substantial heterogeneity between perioperative continuous outcomes (alignments), these outcomes were qualitatively/narratively described. Pooled CPNP rates were log-transformed to calculate 95% Confidence Intervals. Chi2 tests were performed to assess differences between sub-groups. A p-value < 0.05 was considered statistically significant. The Analysis was conducted using R version 4.0.2 (R Foundation statistical computing, Vienna, Austria) with “Metafor package” (Maastricht University, Maastricht, Netherlands).

Results

Twenty-seven studies were included, representing 1397 valgus knees. Nineteen studies performed only a lateral STR and 8 an OT, including 2 studies with an MFEO and 6 studies LFEO (Table 3). All OT studies used also a lateral STR except one [31]. Two studies performed a PNR in addition to their STR [8, 40]. There was female predominance (mean 70.4%, range 29–94%). The pooled mean age was 67.2 ± 9.1 (range 54–74) and the mean BMI ranged from 23 to 30 kg/m2, but was only reported in 6 studies [8, 17, 30, 33, 36, 47]. Preoperative diagnoses included 746 (59.4%) patients with OA, 219 (17.5%) with rheumatoid arthritis, 27 (2.2%) with posttraumatic OA and 263 (21.0%) had an unknown aetiology. Surgery was performed by a medial parapatellar arthrotomy in 16 and a lateral patellar arthrotomy in 11 studies. The weighted mean follow-up was 4.5 years (range, 0.6–10.5).

Quality of the studies

One randomized controlled trial [33] and 26 non-randomized studies were included. The non-randomized studies consisted of 11 prospective and 15 retrospective cohorts. To estimate the risk of bias of the non-randomized studies, the MINORS criteria were calculated. Two comparative studies had a mean MINOR score of 16.5 (range 16–17) out of 24. The other 24 studies were non-comparative studies with a mean of 10.7 (range, 9–13) out of 16. Only 3 studies (11.5%) reported a prospective calculation of the sample size.

Common peroneal nerve palsy ratio

In 27 studies, 26 cases of CPNP were reported over a total of 1397 TKA-V (1.9%) (Table 4). The CPNP ratio was comparable between the studies that performed a PNR in 41 knees and the 17 studies that performed only an STR without PNR in 1123 knees (2.4% vs. 2.1%, p = 0.90). The pooled mean age and female predominance between groups was comparable (70 vs. 67 years and 70% vs. 73%). Also, no significant difference in CPNP rate was found between the studies that performed an STR in 1164 knees and an OT in 233 knees (2.2% vs. 0.4%, p = 0.11). The pooled mean aga and female predominance between the STR and OT group were (67 vs. 70 years, 71% vs. 78%). The study of Conjeski et al. [31] was responsible for the only CPNP case in the entire OT group (n = 233) but was also the single study that used no additional lateral STR and has let the piece of the OT healed in situ without use of internal fixation. Three studies did not explicitly describe CPNP cases in their complication section, therefore it was assumed that CPNP did not occur in those studies [35, 37, 48]. No study clarified if a CPNP case was developed from a patient with posttraumatic OA. Nevertheless, only two studies had patients (11 knees) with posttraumatic OA, where also CPNP cases (7 knees) were reported [15, 16]. Information on whether these CPNP cases occurred in one of these 11 knees was lacking.

Table 4.

Prevalence of common peroneal nerve palsy

Treatment group Studies (n) Patients (No of knees) CPNP cases (%) Pooled proportion (%) 95% CI (%) Heterogeneity I2- (%) P-value
Osteotomy 8 226 (233) 1 (0.4%) 0.43 0.01–2.37 0%
Soft tissue release 19 1029 (1164) 25 (2.2%) 2.15 1.39–3.15 0% 0.11
 PNR 2 37 (41) 1 (2.4%) 2.44 0.06–12.86 46%
 No PNR 17 992 (1123) 24 (2.1%) 2.14 1.37–3.16 2% 0.90
Overall 27 1255 (1397) 26 (1.9%) 1.86 1.22–2.72 0%

No Number of, CPNP Common peroneal nerve palsy, PNR Peroneal nerve release, CI Confidence interval

Soft tissue releases

In the 19 studies that solely performed a lateral STRs, a large variation in released ligaments was present compared with the studies that performed an OT, that mainly released the ITB and PLC. A single study in the OT group performed a POP release [35]. A sub-analysis was performed to approximate the difference in CPNP rate between different specifically released ligaments (Table 5). Between the releases of different ligaments or the manner of those releases (pie-crusting, subperiosteal or transverse), no significant difference in CPNP rate was found. Only studies that reported that all patients underwent a release of a specific ligament were included for sub-analysis. One study was excluded from any analysis due to a lack of data [40].

Table 5.

Specific ligament release and CPNP ratio

Released ligament A Studies (n) Treated knees (%) CPNP cases, (%) P-value
No ITB releases 4 114 (9.7%) 4 (3.5%)
ITB release overall 19 1057 (90.3%) 14 (1.3%) 0.09
 Pie-crusting 6 232 (21.9%) 3 (1.3%)
 Subperiosteal 9 525 (49.7%) 6 (1.1%)
 Transverse 2 208 (19.7%) 1 (0.5%) 0.66
 Unclear A 2 92 (8.7%) 0 (0.0%)
No PLC releases 7 326 (33.2%) 7 (2.1%)
PLC release overall 10 656 (66.8%) 10 (1.5%) 0.60
 Pie-crusting 2 71 (10.8%) 3 (2.4%)
 Transverse 7 553 (84.3%) 7 (1.3%) 0.07
 Unclear A 1 32 (4.9%) 0 (0.0%)
No LCL releases 18 608 (52.7%) 7 (1.2%)
LCL release overall 8 545 (47.3%) 14 (2.6%) 0.08
No POP releases 14 700 (75.7%) 9 (1.3%)
POP release overall 4 225 (24.3%) 5 (2.2%) 0.35

CPNP Common peroneal nerve palsy, ITB Iliotibial band, PLC Posterior lateral capsule, LCL Lateral collateral ligament, POP Popliteus tendon. A: Studies that released a lateral soft tissue, but without specifying in which manner this was performed

Studies that performed a specific ligament release on only a part of the total study population were excluded for analysis. One study [40] was excluded for analysis due to lack of data

Pre and postoperative alignments

The overall weighted mean pre- and postoperative aFTAs was 19.5 ± 8.4 and 5.3 ± 2.7 degrees (Table 6). The PNR group was the only group with a considerable larger weighted mean preoperative aFTA (30.1 ± 1.3), and therefore, a larger Valgus Correction Angle (VCA) (25.0°). All weighted postoperative aFTAs were comparable between the different groups. Due to a high heterogeneity between studies (I2 > 0.80), no statistical analysis could be performed. Regarding to the CPNP cases, 4 studies reported the individual preoperative aFTA of 4 CPNP cases, which were 19° [49], 25° [47], 26° [31] and 38° [40]. Flexion contracture angles were reported in 11 studies (41%), with an overall weighted mean of 4.1 ± 4.8°. No individual flexion contractures of CPNP cases were reported in the studies.

Table 6.

Pre and -postoperative alignments

Studies A Patients (No of knees) Mean preoperative aFTA° ± SD Mean Postoperative aFTA° ± SD mean VCAB
Osteotomy 5 189 (190) 18.5 ± 5.7 6.2 ± 0.7 12.3
Soft tissue releases 19 1029 (1164) 18.6 ± 6.2 5.2 ± 2.5 13.4
 PNR 2 37 (41) 30.1 ± 1.3 5.1 ± 0.3 25.0
 No PNR 17 992 (1123) 19.3 ± 6.1 5.2 ± 2.5 14.1
Overall 24 1212 (1353) 19.5 ± 8.4 5.3 ± 2.7 14.2

CPNP Common peroneal nerve palsy, VCA Valgus correction angle, aFTA Anatomical femorotibial angle

No statistical analysis is performed due to a substantial heterogeneity between the studies. All studies are weighted by the number of operated knees. Three study were excluded due to lack of data [29, 30, 32]. Valgus correction angle is calculated by postoperative aFTA minus preoperative aFTA

Discussion

In this systematic review, the most important finding was the overall CPNP ratio of 1.9% after TKA-V. No significant differences in CPNP rate were found between TKA-V with and without PNR (2.4% vs 2.1%), between TKA-V with lateral STR (2.2%) or with OT (0.4%) and between the releases of different ligaments or the manner of those releases (pie-crusting, subperiosteal or transverse).

The obtained overall CPNP ratio of 1.9% in this study falls within the known range of TKA-V (0.3% - 9.5%) [3, 917]. Other systematic review reported a range of 0.01% to 4.3%, like the one of Carender et al. [2] and Rodríguez-Merchán et al. [50]. Currently, controversy still exists related to valgus deformity being a predisposing factor of CPNP. Studies that have investigated the location of the CPN, indicate that the CPN can be jeopardized by a direct injury due to pie-crusting or a transverse release of the ITB or PLC in well-aligned and valgus knees [19, 20, 51]. However, in our review, we could not confirm the increase of risk to injure the CPN by different ligament releases. Therefore, our results may support the theory that most CPNPs probably occur due to postoperative mechanical damage, like traction and compression, instead of a direct injury. Besides, one large registry-based study by Christ et al. [3], including 383,060 primary TKA procedures, found that preoperative valgus alignments increase the risk of developing a CPNP significantly (OR 4.19). Also, Idusuyi et al. [4], found a relative risk of CPNP 12 times greater for patients with a 12° or more valgus deformity. Both studies did not find an association between CPNP and flexion contractures. However, according to Christ et al. [3], this may be because the diagnosis code for flexion contractures is not consistently noted as that of valgus deformities in their registry. Therefore, the data may be biased. Other studies, like Park et al. [12] and Schinsky et al. [52] found an overall incidence of 0.53% and 1.3% but did not find any relation between valgus deformities and CPNP. However, all these studies used mixed preoperative alignments. Therefore, it is difficult to compare the CPNP ratio of this systematic review, with the incidence of other reviews or studies. Eventually, knowing that larger previous studies showed an increase in CPNP incidence in valgus knees, we would advise clinicians to perform a TKA-V with extra care. This would enable PNR as an option for severe valgus deformities since the procedure is minimally invasive and may lead to preventing CPNP. However, this current review did not find a significant difference in CPNP incidence between the studies that performed a TKA-V with and without PNR. Regarding the 2 studies utilizing a PNR, the study of Cree et al. [40] is a small retrospective study and the recent study of Xu et al. [8] is a small prospective study, both studies performed the same surgical technique. The studies together account for a population of 41 knees in which 1 developed a CPNP. Focussing on that single CPNP case, the study of Cree et al. [40] mentioned that the CPN remained too tight after an extensive PNR due to a vast preoperative aFTA of 38° and VCA of 30°. Therefore, this CPNP developed assumably due to the postoperative stretch of the CPN. Furthermore, comparing the perioperative alignments of the 2 PNR studies with the non-PNR studies show that the preoperative aFTA of the 2 PNR studies is substantially bigger (30.1°. vs 19.3°). However, it is difficult to compare these alignments without any statistical analysis due to the high heterogeneity between the studies. It is noticeable that the 4 individual CPNP cases that are mentioned in the 4 studies, all have a higher preoperative aFTA (19° [49], 25° [47], 26° [31] and 38° [40]) than the overall mean aFTA of all the studies in this review.

In the end, the results in this review suggest that a PNR procedure is not effective. However, it is difficult to assume such an interpretation because only two small sample sized studies were found that used a PNR prior to TKA and met the inclusion criteria of our systematic review [8, 40]. Future research should further investigate PNR in larger study populations and preferably with a comparison group, which would make it easier to interpret results.

Like all studies, some limitations need to be discussed. Firstly, the considerable heterogeneity between the included studies, possibly caused by our caution to minimize selection bias in including studies for this review. However, due to the low incidence of CPNP and the focus on valgus deformities, a comprehensive literature search was needed. Secondly, the review lacks important detailed information about the individual cases who developed a CPNP in the studies. In addition, preoperative data of the knees, like knee extension angles and stress radiographs to assess whether there is a fixed valgus deformity are missing in most studies. Therefore, it is important for future studies to specify the manner and degree of the surgeries and to comprehensively note the pre and postoperative data of the knees. Thirdly, the scarce of studies investigating a PNR is an insurmountable problem, which made it impossible to draw conclusions. However, this review provides a basis for future work investigating PNR in valgus knees to prevent CPNP.

Conclusion

To our knowledge, this is the first systematic review that provides insight into the current literature about preventing CPNP with a PNR after TKA-V. An overall CPNP ratio of 1.9% in valgus knees after TKA was found. There was no direct evidence that using a PNR would be more effective than not using a PNR in preventing a CPNP. However, it was impossible to draw conclusions, due to the scarce amount of literature. Therefore, larger studies comparing TKA-V with and without PNR are needed to appropriately define the efficiency of a PNR. This systematic review is the first step in this regard.

Supplementary Information

40634_2021_443_MOESM1_ESM.pdf (92.1KB, pdf)

Additional file 1. Figure S1. PRISMA flow diagram. The flow diagram of study selection per guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) group.

Acknowledgements

We would like to thank Marjolein Schager of the Spaarne Gasthuis for assistance in drafting the manuscript and Willy Salemink of the Spaarne Gasthuis Library for the librarian-assisted search.

Abbreviations

TKA

Total Knee Arthroplasty

TKA-V

Total Knee Arthroplasty in Valgus deformities of > 10° aFTA

STR

Soft Tissue Release

OT

Osteotomy

ITB

Iliotibial Band

LCL

Lateral Collateral Ligament

PLC

Posterolateral Capsule

POP

Popliteus tendon

CPNP

Common Peroneal Nerve Palsy

CPN

Common Peroneal Nerve

PNR

Peroneal Nerve Release

aFTA

anatomic FemoroTibial Angle

VCA

Valgus Correction Angle

LFEO

Lateral Femoral Epicondyle Osteotomy

MFEO

Medial Femoral Epicondyle Osteotomy

Authors’ contributions

RP performed the literature search, scanned all abstracts and full texts of the included articles, determined the quality of the studies and wrote the manuscript. RR and LK screened all abstracts and full texts as a second author and helped to draft the manuscript. IS provided suggestions on the review process, statistical analyses and manuscript; and checked the data extraction. PN coordinated this study and participated in its design. All authors read and approved the final manuscript.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declarations

Ethics approval and consent to participate

No ethical approval was necessary for this study.

No informed consent was necessary for this study.

Competing interests

None.

Footnotes

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  • 1.Asp JP, Rand JA (1990) Peroneal nerve palsy after total knee arthroplasty. Clin Orthop Relat Res (261):233-237. [PubMed]
  • 2.Carender CN, Bedard NA, An Q, Brown TS. Common peroneal nerve injury and recovery after total knee arthroplasty: a systematic review. Arthroplast Today. 2020;6(4):662–667. doi: 10.1016/j.artd.2020.07.017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Christ AB, Chiu YF, Joseph A, Westrich GH, Lyman S. Incidence and risk factors for peripheral nerve injury after 383,000 Total knee arthroplasties using a New York state database (SPARCS) J Arthroplast. 2019;34:2473–2478. doi: 10.1016/j.arth.2019.05.008. [DOI] [PubMed] [Google Scholar]
  • 4.Idusuyi OB, Morrey BF. Peroneal nerve palsy after total knee arthroplasty. Assessment of predisposing and prognostic factors. J Bone Joint Surg Am. 1996;78:177–184. doi: 10.2106/00004623-199602000-00003. [DOI] [PubMed] [Google Scholar]
  • 5.Poage C, Roth C, Scott B. Peroneal nerve palsy: evaluation and management. J Am Acad Orthop Surg. 2016;24:1–10. doi: 10.5435/JAAOS-D-14-00420. [DOI] [PubMed] [Google Scholar]
  • 6.Görtz S, Guilherme C, Gracitelli, Bugbee WD (2017) 27 - Valgus Malalignment: Diagnosis, Osteotomy Techniques, and Clinical Outcomes. In: Noyes' Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes (Second Edition). Elsevier, p 848-857. 10.1016/B978-0-323-32903-3.00027-5.
  • 7.Ranawat AS, Ranawat CS, Elkus M, Rasquinha VJ, Rossi R, Babhulkar S. Total knee arthroplasty for severe valgus deformity. J Bone Joint Surg Am. 2005;87(Suppl 1):271–284. doi: 10.2106/JBJS.E.00308. [DOI] [PubMed] [Google Scholar]
  • 8.Xu J, Liu H, Luo F, Lin Y. Common peroneal nerve ‘pre-release’ in total knee arthroplasty for severe valgus deformities. Knee. 2020;27:980–986. doi: 10.1016/j.knee.2020.02.012. [DOI] [PubMed] [Google Scholar]
  • 9.Koskinen E, Remes V, Paavolainen P, Harilainen A, Sandelin J, Tallroth K, et al. Results of total knee replacement with a cruciate-retaining model for severe valgus deformity—a study of 48 patients followed for an average of 9 years. Knee. 2011;18:145–150. doi: 10.1016/j.knee.2010.04.001. [DOI] [PubMed] [Google Scholar]
  • 10.Matar HE, Thangaraj R, Saraogi A, Raut V. High medium-term survivorship of cruciate-retaining Total knee arthroplasties (110 knees) for Valgus deformity. J Knee Surg. 2019;34(4):422–426. doi: 10.1055/s-0039-1696956. [DOI] [PubMed] [Google Scholar]
  • 11.Nercessian OA, Ugwonali OF, Park S. Peroneal nerve palsy after total knee arthroplasty. J Arthroplast. 2005;20:1068–1073. doi: 10.1016/j.arth.2005.02.010. [DOI] [PubMed] [Google Scholar]
  • 12.Park JH, Restrepo C, Norton R, Mandel S, Sharkey PF, Parvizi J. Common peroneal nerve palsy following total knee arthroplasty: prognostic factors and course of recovery. J Arthroplast. 2013;28:1538–1542. doi: 10.1016/j.arth.2013.02.025. [DOI] [PubMed] [Google Scholar]
  • 13.Ren J, Zhang X, Wulamu W, Yushan N, Aaimaiti A, Cao L. Total knee arthroplasty with the least-constrained implant possible for type II valgus knee> 20°: a 3–14 years’ follow-up. Arthroplasty. 2020;2:1–7. doi: 10.1186/s42836-020-00036-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Rossi R, Rosso F, Cottino U, Dettoni F, Bonasia DE, Bruzzone M. Total knee arthroplasty in the valgus knee. Int Orthop. 2014;38:273–283. doi: 10.1007/s00264-013-2227-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Satish BR, Ganesan JC, Chandran P, Basanagoudar PL, Balachandar D (2013) Lateral parapatellar approach without tibial tubercle osteotomy for fixed valgus deformity correction in total knee arthroplasty. JBJS Essent Surg Tech 3(4): e20 [DOI] [PMC free article] [PubMed]
  • 16.Stern SH, Moeckel BH, Insall JN (1991) Total knee arthroplasty in valgus knees. Clin Orthop Relat Res (273):5–8 [PubMed]
  • 17.Zhou X, Wang M, Liu C, Zhang L, Zhou Y. Total knee arthroplasty for severe valgus knee deformity. Chin Med J (Engl) 2014;127:1062–1066. [PubMed] [Google Scholar]
  • 18.Aglietti P, Lup D, Cuomo P, Baldini A, De Luca L. Total knee arthroplasty using a pie-crusting technique for valgus deformity. Clin Orthop Relat Res. 2007;464:73–77. doi: 10.1097/BLO.0b013e3181591c48. [DOI] [PubMed] [Google Scholar]
  • 19.Bruzzone M, Ranawat A, Castoldi F, Dettoni F, Rossi P, Rossi R. The risk of direct peroneal nerve injury using the Ranawat “inside-out” lateral release technique in valgus total knee arthroplasty. J Arthroplast. 2010;25:161–165. doi: 10.1016/j.arth.2008.08.016. [DOI] [PubMed] [Google Scholar]
  • 20.Clarke HD, Fuchs R, Scuderi GR, Scott WN, Insall JN. Clinical results in valgus total knee arthroplasty with the “pie crust” technique of lateral soft tissue releases. J Arthroplast. 2005;20:1010–1014. doi: 10.1016/j.arth.2005.03.036. [DOI] [PubMed] [Google Scholar]
  • 21.Lange J, Haas S. Correcting severe valgus deformity: taking out the knock. Bone Joint J. 2017;99:60–64. doi: 10.1302/0301-620X.99B1.BJJ-2016-0340.R1. [DOI] [PubMed] [Google Scholar]
  • 22.Cheng W, Li Z, Zhang J, Cao Q, Yu H, Qi L, et al. A lateral parapatellar approach with iliotibial band dissection from the Gerdy tubercle for total knee arthroplasty of the valgus knee. Exp Ther Med. 2021;21:38. doi: 10.3892/etm.2020.9470. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Elkus M, Ranawat CS, Rasquinha VJ, Babhulkar S, Rossi R, Ranawat AS. Total knee arthroplasty for severe valgus deformity: five to fourteen-year follow-up. JBJS. 2004;86:2671–2676. doi: 10.2106/00004623-200412000-00013. [DOI] [PubMed] [Google Scholar]
  • 24.Li H, Ponzio DY, Ong A, Wei W, Wang B, Li Z, et al. Total knee arthroplasty for fixed valgus deformity correction using a modified lateral parapatellar approach. J Knee Surg. 2020;33:372–377. doi: 10.1055/s-0039-1677821. [DOI] [PubMed] [Google Scholar]
  • 25.Rajgopal A, Dahiya V, Vasdev A, Kochhar H, Tyagi V. Long-term results of total knee arthroplasty for valgus knees: soft-tissue release technique and implant selection. J Orthop Surg. 2011;19:60–63. doi: 10.1177/230949901101900114. [DOI] [PubMed] [Google Scholar]
  • 26.Apostolopoulos AP, Nikolopoulos DD, Polyzois I, Nakos A, Liarokapis S, Stefanakis G, et al. Total knee arthroplasty in severe valgus deformity: interest of combining a lateral approach with a tibial tubercle osteotomy. Orthop Traumatol Surg Res. 2010;96:777–784. doi: 10.1016/j.otsr.2010.06.008. [DOI] [PubMed] [Google Scholar]
  • 27.Greenberg A, Kandel L, Liebergall M, Mattan Y, Rivkin G. Total knee arthroplasty for Valgus deformity via a lateral approach: clinical results, comparison to medial approach, and review of recent literature. J Arthroplast. 2020;35:2076–2083. doi: 10.1016/j.arth.2020.03.037. [DOI] [PubMed] [Google Scholar]
  • 28.Whiteside LA (1999) Selective ligament release in total knee arthroplasty of the knee in valgus. Clin Orthop Relat Res 367:130–140 [PubMed]
  • 29.Brilhault J, Lautman S, Favard L, Burdin P. Lateral femoral sliding osteotomy: lateral release in total knee arthroplasty for a fixed valgus deformity. J Bone Joint Surg Br. 2002;84:1131–1137. doi: 10.1302/0301-620x.84b8.12824. [DOI] [PubMed] [Google Scholar]
  • 30.Cheng X, Wang Z, Zhang Y, Wang M, Zhang X. Tightening medial collateral ligament during total knee arthroplasty for patients with fixed valgus deformity: a novel technique. J Orthop Surg (Hong Kong) 2019;27:2309499019834695. doi: 10.1177/2309499019834695. [DOI] [PubMed] [Google Scholar]
  • 31.Conjeski JM, Scuderi GR. Lateral femoral Epicondylar osteotomy for correction of fixed Valgus deformity in Total knee arthroplasty: a technical note. J Arthroplast. 2018;33:386–390. doi: 10.1016/j.arth.2017.09.018. [DOI] [PubMed] [Google Scholar]
  • 32.Hadjicostas PT, Soucacos PN, Thielemann FW. Computer-assisted osteotomy of the lateral femoral condyle with non-constrained total knee replacement in severe valgus knees. J Bone Joint Surg Br. 2008;90:1441–1445. doi: 10.1302/0301-620X.90B11.20092. [DOI] [PubMed] [Google Scholar]
  • 33.Mou P, Zeng Y, Pei F, Zhou Z, Shen B, Kang P, et al. Medial femoral epicondyle upsliding osteotomy with posterior stabilized arthroplasty provided good clinical outcomes such as constrained arthroplasty in primary total knee arthroplasty with severe valgus deformity. Knee Surg Sports Traumatol Arthrosc. 2019;27:2266–2275. doi: 10.1007/s00167-018-5292-9. [DOI] [PubMed] [Google Scholar]
  • 34.Mullaji AB, Shetty GM. Lateral epicondylar osteotomy using computer navigation in total knee arthroplasty for rigid valgus deformities. J Arthroplast. 2010;25:166–169. doi: 10.1016/j.arth.2009.06.013. [DOI] [PubMed] [Google Scholar]
  • 35.Raut V, Matar HE, Singh A. Satisfactory medium-term outcomes with lateral condylar sliver osteotomy to correct valgus deformity in total knee replacements. Knee Surg Sports Traumatol Arthrosc. 2020;28:1394–1399. doi: 10.1007/s00167-019-05488-1. [DOI] [PubMed] [Google Scholar]
  • 36.Scior W, Hilber F, Hofstetter M, Graichen H. Short-term and mid-term results of lateral condyle sliding osteotomy in the treatment of valgus total knee arthroplasty: a successful therapy option in grade 2 valgus total knee arthroplasty. Knee. 2018;25:466–472. doi: 10.1016/j.knee.2018.03.007. [DOI] [PubMed] [Google Scholar]
  • 37.Strauch M, von Eisenhart RR, Graichen H. A new navigation-based technique for lateral distalizing condylar osteotomy in patients undergoing total knee arthroplasty with fixed valgus deformity. Knee Surg Sports Traumatol Arthrosc. 2013;21:2263–2270. doi: 10.1007/s00167-012-2112-5. [DOI] [PubMed] [Google Scholar]
  • 38.Ang CL, Fook S, Chia SL, Chin PL, Lo NN, Yeo SJ. Unconstrained arthroplasty in type II valgus knees: posterior stabilized or cruciate retaining? Knee Surg Sports Traumatol Arthrosc. 2014;22:666–673. doi: 10.1007/s00167-013-2677-7. [DOI] [PubMed] [Google Scholar]
  • 39.Easley ME, Insall JN, Scuderi GR, Bullek DD (2000) Primary constrained condylar knee arthroplasty for the arthritic valgus knee. Clin orthop Relat Res 380(2):58–64 [DOI] [PubMed]
  • 40.Cree AK, Coolican MR, Tonkin MA. Prevention of common peroneal nerve palsy after surgery for valgus deformity about the knee. Knee. 1998;5:261–265. [Google Scholar]
  • 41.Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ. 2009;339:b2700. doi: 10.1136/bmj.b2700. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42.Ouzzani M, Hammady H, Fedorowicz Z, Elmagarmid A. Rayyan — a web and mobile app for systematic reviews. Systematic Reviews (2016) 5:210. 10.1186/s13643-016-0384-4. [DOI] [PMC free article] [PubMed]
  • 43.Prill R, Karlsson J, Ayeni OR, Becker R. Author guidelines for conducting systematic reviews and meta-analyses. Knee Surg Sports Traumatol Arthrosc. 2021;29:2739–2744. doi: 10.1007/s00167-021-06631-7. [DOI] [PubMed] [Google Scholar]
  • 44.Slim K, Nini E, Forestier D, Kwiatkowski F, Panis Y, Chipponi J. Methodological index for non-randomized studies (minors): development and validation of a new instrument. ANZ J Surg. 2003;73:712–716. doi: 10.1046/j.1445-2197.2003.02748.x. [DOI] [PubMed] [Google Scholar]
  • 45.Hozo SP, Djulbegovic B, Hozo I. Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol. 2005;5:13. doi: 10.1186/1471-2288-5-13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46.Walter SD, Yao X. Effect sizes can be calculated for studies reporting ranges for outcome variables in systematic reviews. J Clin Epidemiol. 2007;60:849–852. doi: 10.1016/j.jclinepi.2006.11.003. [DOI] [PubMed] [Google Scholar]
  • 47.Boettner F, Renner L, Arana Narbarte D, Egidy C, Faschingbauer M. Total knee arthroplasty for valgus osteoarthritis: the results of a standardized soft-tissue release technique. Knee Surg Sports Traumatol Arthrosc. 2016;24:2525–2531. doi: 10.1007/s00167-016-4054-9. [DOI] [PubMed] [Google Scholar]
  • 48.Guo C, Liu J, Niu D, Ma J, Kou B, Zhang H, et al. Clinical application of different operative approach of total knee replacement in knee valgus patients. Retrospective cohort study. Int J Surg. 2018;49:80–83. doi: 10.1016/j.ijsu.2017.12.008. [DOI] [PubMed] [Google Scholar]
  • 49.Chechik O, Mayer C, Drexler M, Sternheim A, Snir N, Dekel S. Posterolateral capsular release for correction of valgus deformity. J Knee Surg. 2012;25:355–360. doi: 10.1055/s-0031-1299668. [DOI] [PubMed] [Google Scholar]
  • 50.Rodríguez-Merchán EC, De la Corte-Rodríguez H, Encinas-Ullán CA. Peroneal nerve palsy after Total knee arthroplasty: prevalence, risk factors, diagnosis and management. In: Rodríguez-Merchán EC, Gómez-Cardero P, editors. Comprehensive treatment of knee osteoarthritis: recent advances. Cham: Springer International Publishing; 2020. pp. 135–142. [Google Scholar]
  • 51.Yang D, Shao H, Zhou Y, Tang H, Guo S. Location of the common peroneal nerve in Valgus knees-is the reported safe zone for well-aligned knees applicable? J Arthroplast. 2017;32:3539–3543. doi: 10.1016/j.arth.2017.05.048. [DOI] [PubMed] [Google Scholar]
  • 52.Schinsky MF, Macaulay W, Parks ML, Kiernan H, Nercessian OA. Nerve injury after primary total knee arthroplasty. J Arthroplast. 2001;16:1048–1054. doi: 10.1054/arth.2001.26591. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

40634_2021_443_MOESM1_ESM.pdf (92.1KB, pdf)

Additional file 1. Figure S1. PRISMA flow diagram. The flow diagram of study selection per guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) group.


Articles from Journal of Experimental Orthopaedics are provided here courtesy of Wiley

RESOURCES