A Systematic Review of Surgical Treatment for Refractory Patellar Tendinopathy

Abstract

Introduction:

With the advent of new classification systems and surgical options, clarification is needed regarding the most effective surgical management for refractory patellar tendinopathy (PT). The objective of this systematic review is to investigate outcomes of surgical management of refractory PT.

Methods:

PubMed was searched from January 1, 2000, through July 12, 2021, using the Medical Subject Headings function and the following Boolean operators: “Patellar Ligament/surgery”[Mesh] NOT “Anterior Cruciate Ligament”[Mesh]. Original research articles that discussed surgical management of PT were included, and outcomes were recorded.

Results:

Fifteen studies (2 studies level 1 and 13 studies level 4) were included comprising 485 patients with an average age of 29.5 years and 523 patellar tendons treated. The seven studies reporting both preoperative and postoperative Victorian Institute of Sports Assessment scores demonstrated increases of 39.60, whereas the seven studies reporting visual analog scores demonstrated decreases of 6.11. Average return-to-play rate was 87.08%. Study designs and in surgical techniques were heterogenous, which precluded the ability to perform a meta-analysis.

Discussion:

Surgical treatment of refractory PT leads to notable improvement in patient-reported outcomes and high return-to-play rates. However, there is a paucity of high-quality research investigating newer surgical options and classification systems for PT.

Epidemiology and Pathophysiology

Patellar tendinopathy (PT), sometimes referred to as patellar tendinosis, patellar tendinitis, or Jumper knee, is a common cause of anterior knee pain that affects up to 14% of athletes and is most prevalent in jumping sports, such as basketball and volleyball.^1,2 Although Jumper knee has been used as a blanket term to include a range of conditions, such as pain at the insertion of the quadriceps tendon, pain at the distal patellar pole, and pain at the tibial tubercle, PT is more specifically used to describe pain secondary to the insertion of the patellar tendon at the distal pole of the patella and is the focus of this review. In addition, studies have demonstrated that rather than an inflammatory condition indicated by the term tendinitis, it is a chronic degenerative condition that results from microtears and cell death from a repetitive loading of the tendon during cutting, repetitive acceleration, and jumping motions.^1-3 Histologically, loss of collagen bundle organization and mucoid degeneration are identified in affected tendons, particularly at the proximal insertion. Hypercellularity, neovascularization, and relative absence of inflammatory cells are common findings as well.⁴

Patellar tendinopathy has been shown to affect men at twice the rate of women and can be an extremely debilitating condition that causes high rates of delayed return to sport and may ultimately be the cause of retirement in more than 50% of athletes with the condition.^2,5 Besides affecting training and performance levels during competition, PT can lead to persistent pain that affects daily activities and in severe cases can even lead to patellar tendon rupture.^5,6

The cause of PT was previously postulated to be secondary to an adaptational change by the tendon in response to compressive forces of the inferior patellar pole on the posterior aspect of the tendon during knee flexion, weakening the tendon over time.⁷ However, that theory was never rigorously tested until Lavagnino et al⁸ demonstrated through a biomechanical cadaver study that tendon attenuation was actually a result of tensile forces at the distal pole insertion, as well as a decreased patella-patellar tendon angle causing microdamage at the proximal tendon.

Diagnosis and Classification

The diagnosis of PT was originally solely a clinical one comprising symptoms and distal patellar pole tenderness. Blazina in 1973 coined the term “Jumper's knee” to highlight the prevalence of PT in jumping activities and formulated a classification system to indicate the severity of PT on a scale of I to IV.⁶ This system ranges from Blazina I, which is pain after exercise through Blazina IV, which was added later to indicate patellar tendon rupture.^6,9 To supplement the clinical diagnosis, both ultrasonography and magnetic resonance imaging have been used to demonstrate tendon thickening and changes at the distal patellar pole.^10,11 After Blazina, the Victorian Institute of Sport Assessment for the patellar tendon (VISA-P) score was developed to better quantify the severity and response to the treatment of PT. Victorian Institute of Sport Assessment for the patellar tendon is a series of eight questions used to generate a score out of 100, with a score of 100 representing the fewest symptoms.¹²

More recently, the Popkin-Golman Classification was developed as a novel classification system to more objectively characterize the severity of PT by factoring in the size and location of partial patellar tendon tears (PPTT) when present and to also establish tendon thickness as a predictor of PPTT.¹³ In their study, it was found that tendon thickness >8.8 mm strongly correlated with a PPTT and that athletes with a tendon thickness greater than 11.5 mm or >50% tear thickness (ie, Popkin-Golman grade 4 PPTT) on axial MRI were unlikely to improve with nonsurgical management.¹³ This provides an objective measure to better triage athletes toward or away from surgical management for their PT.

Management Options

A number of treatment options for PT have been evaluated and prior classification systems such as that developed by Blazina have been used to guide treatment decisions. However, there is no clear consensus as to which strategy is most effective. With the development of new classification systems such as the Popkin-Golman score, surgeons may be better able to identify the ideal treatment approach. Nonsurgical treatment ranges from physical therapy with eccentric quadriceps exercises to injections with corticosteroids or sclerosing agents, extracorporeal shock wave therapy, and platelet-rich plasma injections.^14-17

For cases refractory to nonsurgical management, open versus arthroscopic surgical techniques have been described. These include débridement of pathologic tissue, bone or tendon resection at the inferior patellar pole, denervation of the infrapatellar pole, primary suture or suture anchor repair, and augmentation of the patellar tendon with suture, wire, allograft, or autograft.¹⁸ Débridement techniques attempt to remove degenerative tissue and stimulate healing of the inferior patellar pole and patellar tendon. Repair and augmentation techniques attempt to reapproximate the patellar tendon and increase its tensile strength.

Prior studies have identified promising outcomes with surgical intervention in the appropriate patient cohorts, and with the advent of new classification systems and treatment modalities, as well as standardized outcome reporting such as VISA-P and visual analog scale (VAS) for pain scores, it is increasingly important to continue analyzing optimal treatment options for patients across all levels of PT severity. The purpose of this systematic review is to compile and analyze all studies investigating surgical intervention for recalcitrant PT with standardized outcome measures to lay the groundwork for future analyses of surgical PT treatment modalities.

Methods

Using the guidelines presented by the updated 2020 Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, the authors conducted a search to identify all articles relevant to the surgical management of PT.¹⁹ The PubMed database was searched from January 1, 2000, through July 12, 2021, using the Medical Subject Headings function. The search criteria using Boolean operators was as follows: “Patellar Ligament/surgery”[Mesh] NOT “Anterior Cruciate Ligament”[Mesh].

Included studies were original research articles (randomized controlled trials, cross-sectional studies, and prospective and retrospective observational studies) that discussed surgical management of PT. All studies from before the year 2000, and all biomechanical, cadaveric, animal model, review, case report, commentary, and technique studies were excluded. Additional exclusion criteria were studies that involved complete patellar tendon tears, nonsurgical management, or studies that did not report either VAS or VISA-P scores.

Two independent reviewers followed the aforementioned search criteria, and simultaneously reviewed the titles, articles, and abstracts, discussing any discrepancies that were identified in real time. The primary outcome of interest was the change in VAS and VISA-P score reported pre- and postintervention in each study group, with a secondary outcome of return to play (RTP) if it was reported, and any other outcome measures when relevant. RTP was defined as the return to preinjury level of play. One author collected data from each of the 15 studies, including publication date, type of study, number of patients and knees, level of evidence, specific surgical techniques evaluated, average age, level of play, mean follow-up length, and outcome measures, including the VAS, VISA-P, and any other outcome scores reported. VAS, VISA-P, and RTP numbers were pooled, and weighted averages were calculated when the appropriate data were available. Statistical analyses were done using Microsoft Excel version 16.0 (Microsoft).

Results

Study Identification

A total of 877 articles were found during the initial literature review. Based on the title alone, 558 articles were excluded. One hundred nineteen were anterior cruciate ligament–related studies, 172 involved the patellofemoral ligament, 27 involved the posterior cruciate ligament, and 240 involved other irrelevant procedures or body parts not related to this review. The second round of screening of the remaining 319 abstracts excluded 269 articles based on the following criteria: wrong procedure or body structure (180), nonsurgical management (53), animal studies (19), epidemiological studies (8), and cadaver studies (9). The final round of screening involved full-text articles, and 50 were assessed for inclusion. Thirty-five were excluded for the following reasons: three involved tendon ruptures, 12 were review articles, two were commentaries, six were technique articles, three were from before the year 2000, one was a case report, five did not include either VAS or VISA-P scores, and three involved percutaneous techniques outside the scope of this review. This resulted in a total of 15 studies that met all inclusion criteria.^20-34 Two studies were level 1 evidence, whereas the other 13 were level 4. The overall search process is illustrated in Figure 1. Quality of each study was assessed with a modified Coleman methodology score and can be found in Tables 1 and 2.

Figure 1.

Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow diagram showing the search process. Adapted from: Page MJ, McKenze JE, Bossut PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021; 372:n71. doi: 10.1136/bmj.n71.

Table 1.

Studies With Victorian Institute of Sport Assessment for the Patellar Tendon Outcomes for Surgically Treated Patellar Tendinopathy

PMID	Author and Year	Methodology	Level of Evidence	Modified Coleman Methodology Score	Participants	Duration of Symptoms	Follow-up	Surgical Procedure	Results	Return to Play?
29685503	Lee et al25 2018	Retrospective case series, 42 patellar tendons treated	4	73	Average age 20.3 (16-25) years, 32 male and 5 female patients	NR	51.3 ± 14.8 months	Arthroscopic débridement, decortication of inferior patellar pole	VISA-P increased from 55.9 ± 11.4 to 95.6 ± 12.1 (P < 0.001)	86.5%
21705648	Pascarella et al28 2011	Prospective case series, 73 patellar tendons treated	4	92	Average age 24.6 (16-35) years, 40 male 24 female patients	NR	5 years	Arthroscopic débridement, lower patellar pole excision	VISA-P increased from 35.6 ± 3.4 to 68.7 ± 4.1 (P < 0.01)	70.4%
23738308	Alaseirlis et al20 2013	Prospective case series, 11 patellar tendons treated	4	79	Average age 24.8 ± 3.4 years, 3 male and 8 female patients	13.5 ± 6 months	17.4 ± 4 months	Arthroscopic débridement, lower patellar pole excision	VISA-P increased from 41.2 ± 5.1 to 86.8 ± 14.9 (P < 0.01)	100%
23830221	Maier et al27 2013	Prospective case series, 30 patellar tendons treated	4	92	Average age 27.6 ± 7.4 years, 27 male and 3 female patients	NR	4.4 ± 3 years	Arthroscopic débridement, tendon release at inferior pole	VISA-P increased from 57.3 ± 11.4 to 95.2 ± 8.2 (P < 0.01)	76.7%
29166934	Lang et al24 2017	Retrospective case series, 30 patellar tendons treated	4	95	Average age 28.2 ± 8.13 years, 26 male and 4 female patients	NR	8.8 ± 2.82 years	Arthroscopic synovectomy, fat pad resection, inferior pole denervation	VISA-P increased from 55.6 ± 12.4 to 95.4 ± 8.1 (P < 0.0001)	80%
29806056	Pestka et al30 2018	Prospective case series, 54 patellar tendons treated	4	92	Average age 27.5 (16-52) years, 43 male and 11 female patients	NR	6.6 (2-18) years	Arthroscopic tendon release at inferior pole	VISA-P increased from 48.8 to 94.0 (P < 0.0001)	74.1%
10750994	Coleman et al22 2000	Retrospective case series, 29 patellar tendons in open tenotomy group, 25 tendons in arthroscopic group	4	92	Average age 27 ± 8 years, 39 male and 9 female patients	18 months	4.0 ± 1.3 years	Arthroscopic versus open débridement	VISA-P increased from (NR) to 88 (22-100) in open group, (NR) to 77 (38-100) in arthroscopic group	60%
16882889	Bahr et al21 2006	Randomized controlled trial, 20 patellar tendons in eccentric training group, 20 tendons in open débridement group	1	88	Average age 30.5 (19-49) years, 31 male and 4 female patients	33 ± 28 months for eccentric group, 35 ± 30 for surgical group	12 months	Comparison of eccentric training versus tendon débridement	Combined VISA-P increased from 30 (25-35) to 70 (62-78)	45% in surgical group, 55% in nonsurgical group
12629424	Peers et al29 2003	Retrospective case series, 13 patellar tendons in open tenotomy group, 14 tendons in shock wave therapy group	4	69	Average age 27.3 years, 21 male and 6 female patients	11.8 ± 7.6 months for shock wave group, 13.9 ± 8.2 months for surgical group	24 months	Extracorporeal shock wave therapy versus open tenotomy	VISA-P increased from (NR) to 70.7 ± 22.2 for surgical group, (NR) to 78.8 ± 28.6 for shock wave group (P > 0.05)	54% in surgical group, 57% in shock wave group

NR = not reported, VISA-P = Victorian Institute of Sport Assessment for the patellar tendon

Table 2.

Studies With Visual Analog Scale Outcomes for Surgically Treated Patellar Tendinopathy

PMID	Author and Year	Methodology	Level of Evidence	Modified Coleman Methodology Score	Participants	Duration of Symptoms	Follow-up	Surgical Procedure	Results	Return to Play?
17151848	Willberg et al32 2007	Prospective case series, 15 patellar tendons treated	4	73	Average age 30 (18-49) years, 12 male and 3 female patients	27 months	13 months	Arthroscopic débridement with ultrasonography localization	VAS decreased from 7.9 (6.2-9.6) to 1.2 (P < 0.05)	87%
21393261	Willberg et al33 2011	Randomized controlled trial, 26 patellar tendons in injection group, 26 tendons in arthroscopic débridement group	1	91	Average age 26 (16-38) years, 49 male and 3 female patients	20 (8-60) months in injection group, 24 (6-60) months in arthroscopic group	12 months	Arthroscopic débridement versus sclerosing injections	VAS scores NR but markedly lower VAS in arthroscopic versus injection group	NR
18237700	Lorbach et al26 2008	Prospective case series, 20 patellar tendons treated	4	70	Average age 28.1 (17-43) years, 18 male and 2 female patients	25 (12-48) months	2 years	Arthroscopic débridement, lower patellar pole resection	VAS NR but markedly improved in all patients (P < 0.01)	100%
24427403	Gill et al23 2013	Retrospective case series, 37 patellar tendons treated	4	70	Average age 29 (14-51) years, 22 male and 12 female patients	NR	3.8 ± 1.6 years	Combined arthroscopic and open débridement, patellar pole microfracture	VAS decreased from 7 ± 2 to 2 ± 2 (P < 0.001)	NR
27028381	Zhang et al38 2016	Retrospective case series, 14 patellar tendons treated	4	63	Average age 45.3 (38-54) years, 8 males, 4 females	NR	24.8 (14-44) months	Combined open patellar tendon tenotomy and débridement with suture-bridge double row repair	VAS decreased by a mean of 6.7(1.1-7.8) points (P < 0.01)	NR
31694130	Ren et al31 2019	Retrospective case series, 24 patellar tendons treated	4	63	Average age 47.2 (32-63) years, 10 male and 8 female patients	NR	35.7 (24-64) months	Open débridement, double row fixation	VAS decreased from 7.5 ± 1.6 to 1.4 ± 1.0(P < 0.001)	NR
23830221	Maier et al27 2013	Prospective case series, 30 patellar tendons treated	4	92	Average age 27.6 ± 7.4 years, 27 male and 3 female patients	NR	4.4 ± 3 years	Arthroscopic débridement, tendon release at inferior pole	VAS decreased from 5.7(4-9) to 0.6 (0-4) (P < 0.01)	77%
29166934	Lang et al24 2017	Retrospective case series, 30 patellar tendons treated	4	95	Average age 28.2 ± 8.13 years, 26 male and 4 female patients	NR	8.8 ± 2.82 years	Arthroscopic synovectomy, fat pad resection, inferior pole denervation	VAS decreased from 5.73 ± 1.31 to 0.5 ± 1.01 (P < 0.0001)	80%
12629424	Peers et al29 2003	Retrospective case series, 13 patellar tendons in open tenotomy group, 14 tendons in shock wave therapy group	4	69	Average age 27.3 years, 21 male and 6 female patients	11.8 ± 7.6 months for shock wave group, 13.9 ± 8.2 months for surgical group	24 months	Extracorporeal shock wave therapy versus open tenotomy	VAS decreased from NR to 2 for surgical group, 1 for shockwave group	NR

NR = not reported, VAS = visual analog scale

Demographics and Procedures

The 15 studies included in this review involved 485 patients and 523 patellar tendons. Average age across all studies weighted by the number of patients per study was 29.5 years. Studies included a mix of recreational (208), professional (180), and not specified (114) athletes. The weighted mean follow-up was 45.4 months, and average duration of symptoms was 21.2 months. All studies included either the VISA-P score or the VAS score as outcome indicators. In addition, 10 studies included various other outcome measures such as the Lysholm score, the Tegner score, the Blazina score, and the Kujala score. Nine studies including VISA-P scores for analysis were included and can be found in Table 1, whereas nine studies including VAS scores can be found in Table 2. Average modified Coleman methodology score was 80.13.

Study Design

Because of the variability in study design and in outcome measures reported, a meta-analysis was not possible in this review. Study methods ranged from retrospective case series (7) to prospective case series (6) to prospective randomized controlled trials (2). Surgical methodology also varied and involved both arthroscopic and open procedures of varying technique. Ten studies involved arthroscopy and included the following: arthroscopic débridement, débridement with patellar pole excision, débridement with decortication of patellar pole, débridement with tendon release at inferior pole, débridement with denervation of patellar pole, and débridement with patellar pole microfracture. Four studies investigated open débridement and ranged from open débridement to open débridement combined with suture-bridge double row fixation. One study investigated a combined arthroscopic and open débridement. One of the randomized controlled trials compared nonsurgical eccentric training with open débridement, whereas the other compared arthroscopic débridement with sclerosing injections.

Victorian Institute of Sport Assessment for the Patellar Tendon Outcomes

Each of the seven studies that reported baseline and postoperative VISA-P scores as an outcome saw a notable increase in VISA-P score after the intervention (weighted average increase of 39.58 points or 87.33%). Two studies that discussed VISA-P scores did not report baseline scores but also described notable increases postoperatively. The weighted average increase in VISA-P scores for arthroscopic procedures alone was 39.60 (82.53%) from the preoperative average. Bahr et al²¹ conducted the only study that reported that VISA-P scores change following open surgery, and they demonstrated a mean increase from 31 to 73 (135.48%) in a cohort of 20 patients. Coleman et al²² directly compared arthroscopic débridement with open débridement and saw a notable increase in VISA-P scores for both groups at the final follow-up with no notable difference between the groups.

Of the studies that used tendon débridement with bony resection, the weighted average VISA-P score increased from 43.25 preoperatively to 80.66 postoperatively (86.50% increase). Three studies used the arthroscopic patellar release (APR) technique, which involved no tendon or patellar resection and resulted in a VISA-P weighted average increase from 52.83 preoperatively to 94.66 postoperatively (79.19% increase). Only the aforementioned study by Bahr et al²¹ evaluated patellar tendon débridement alone.

The only trial comparing surgical versus nonsurgical eccentric training was once again the randomized control trial by Bahr et al,²¹ which showed notable increases in VISA-P scores but no notable difference between open surgical patellar tendon débridement (42 points, 135.48%) and nonsurgical management (37 points, 127.59%). Of note, however, five of the 20 patients (25%) from the nonsurgical cohort ended up requiring surgery after the eccentric training protocol failed to resolve their symptoms. These patients did not demonstrate any notable improvement in the VISA-P score during the twelve-month period. Victorian Institute of Sport Assessment for the patellar tendon changes from each individual study can be found in Table 1.

Visual Analog Scale Pain Outcomes

The seven studies reporting baseline and postoperative VAS pain as an outcome saw a notable decrease in VAS score after surgical intervention (weighted VAS decrease of 6.11 points or 82.56%). Two studies only reported postoperative VAS scores, and one study did not publish scores but mentioned a notable decrease in scores post-intervention. The one study where arthroscopic tendon débridement without patellar resection or patellar tendon repair was performed saw a −6.00 (−74.07%) decrease in VAS score after treatment. Lorbach et al²⁶ published the only study analyzing inferior patellar pole resection without tendon débridement, and found a mean decrease of −5.55 (−78.72%). The three studies that used APR found a weighted mean VAS decrease of −5.51 point (−89.19%) from the preoperative average. Finally, the two studies that analyzed patellar tendon débridement with inferior patellar pole resection demonstrated a weighted mean VAS decrease of −5.43 (−75.49%).

Willberg et al³³ conducted a randomized control trial comparing arthroscopic débridement to sclerosing injections and analyzed VAS scores pre- and posttreatment. They mentioned a markedly greater decrease in VAS scores and markedly higher patient satisfaction scores in the arthroscopically treated cohort at 12 months of follow-up but did not report preoperative VAS scores. VAS score changes from each individual study can be found in Table 2.

Return to Play and Additional Outcomes

For the 10 studies that reported RTP, the average weighted RTP was 87.08%. From these same 10 studies, the average weighted RTP at preinjury level was 68.26%. Only eight of these studies reported mean time to RTP, with a mean time to RTP from these studies of 4.63 months.

Five studies reported Lysholm scores, and the weighted average preoperative Lysholm score was 52.57. This increased to a weighted average of 94.22 postoperatively, representing an increase of 79.25%. Three studies reported Tegner scores, with weighted average increasing from 5.89 preoperatively to 7.62 postoperatively (29.47% increase). Two studies reported International Knee Documentation Committee scores, with the weighted average score increasing from 51.44 preoperatively to 89.21 postoperatively (73.43% increase). Finally, two studies reported Kujala scores, with the weighted average increasing from 52.42 preoperatively to 96.01 postoperatively (83.31% increase).

Discussion

This systematic review was done to provide an updated review of the literature regarding the surgical management of PT and to evaluate these studies with the validated VISA-P and VAS assessment tools.^12,35 Furthermore, these studies are discussed in the context of the novel Popkin-Golman classification system so that future studies may help further establish specific indications for surgical management in PT. Standard indications for surgical management in PT have been Blazina stage III disease with recalcitrant pain and dysfunction following roughly 6 months of nonsurgical treatment.²⁷ Popkin-Golman grade 4 tears, which represent tears that are >50% of the total tendon thickness, are also indicated for surgery after 6 months of failed nonsurgical management.¹³ A range of surgical techniques were discussed in the included studies. Each of the described techniques involved some combination of patellar tendon débridement and/or patellar resection, except for the three studies using APR. Interestingly, only two studies involved the use of suture anchors.

When evaluating all studies in this analysis that used VISA-P scores, notable increases in mean VISA-P score after intervention were identified in each study (weighted average increase of 39.58 points or 87.33%). No identifiable difference was observed between different techniques, however, especially because a meta-analysis was unable to be done. Even when looking only at arthroscopic surgeries, or only at surgeries involving isolated patellar tendon débridement, notable heterogeneity existed from study to study.

The least invasive surgical technique discussed in the VISA-P cohort was APR, which involves removal of the infrapatellar fat pad and denervation of the inferior patellar pole with bipolar electrocautery.^24,27,30,36 Importantly, this is the only technique analyzed that involves no débridement of the patellar tendon or inferior patellar pole. The 94.66 weighted mean VISA-P score following this procedure suggests that this minimally invasive technique can achieve adequate results from a patient-reported outcome standpoint. Ultimately, all surgical techniques resulted in large and statistically significant increases in VISA-P within each respective study, and successful results were achieved with both open and arthroscopic techniques.

Similarly, when evaluating all techniques that discussed VAS scores, large decreases in pain were identified in each study (weighted VAS decrease of 6.11 points, −82.56%). In regard to pain reduction, more invasive techniques involving excessive débridement or use of suture anchors may not be needed in comparison to minimally invasive techniques that achieve denervation of the inferior patellar pole. However, when comparing surgical with nonsurgical management, arthroscopic patellar tendon débridement resulted in a larger VAS decrease compared with sclerosing injections in a cohort of patients with PT that did not resolve with at least 3 months of rest, anti-inflammatory medication, and eccentric training.³³ This is in concordance with previous evidence that patients with intractable symptoms generally benefit from surgery versus continued nonsurgical management.

Overall, the studies included in this review featured a high RTP rate (87.08%) following surgical intervention. Of the eight studies that reported duration until RTP, the weighted average rehabilitation period was 4.63 months. This is consistent with RTP rates cited in other reviews; Brockmeyer et al³⁷ found a return to sport rate of 82.3% at an average of 3.9 months after arthroscopic surgery and 78.4% at an average of 8.3 months after open surgery. As the authors of this study did not perform a meta-analysis, they are unable to identify differences in RTP rates between various open and arthroscopic techniques. In addition, among the limited number of studies that reported Lysholm, Tegner, International Knee Documentation Committee, and Kujala scores, there are average increases of 79.25%, 29.47%, 73.43%, and 83.31%, respectively. Although revision surgery rate was low at 8.43%, the most common reasons for failed surgical treatment and revision surgery included the inability to return to sport and persistent pain.^24,27,30

Ultimately, the literature does not support any one surgical technique as the benchmark procedure but instead suggests that both open and arthroscopic débridement, tendon/bony resection, and/or repair with suture anchors are relatively safe and effective procedures. This review identified no notable differences between different approaches and procedures when comparing the outcome measures reported in the included literature, although meta-analysis was unable to be conducted. All surgical techniques resulted in increased VISA-P,^{20-22,24,25,27-30} decreased VAS pain scores,^{23,26,31-33,38} improvements in functional outcomes measures,^{20,23,25,26,28,38} high rate of RTP with most athletes returning to prior performance level, and relatively low rate of revision surgery.

None of the studies evaluated primary suture repair, which was initially described in the management of patellar tendon ruptures but can be used for PPTT as well.²³ Similarly, suture anchors are commonly used in the treatment of patellar tendon complete ruptures but can also be used in PPTT to decrease the risk of tear progression or complete rupture. Finally, no studies were found meeting inclusion criteria that evaluated the use of autograft augmentation or reconstruction. An important example of this is the semitendinosus autograft augmentation described by Woodmass et al.³⁴ This technique theoretically provides the strongest fixation, which facilitates earlier mobilization and reduced risk of tear progression. Disadvantages include donor-site morbidity, increased surgical time, and risk of patellar fracture during seating of graft. Ultimately, the evidence provided in the present review shows that simple débridement of pathologic tissue or denervation of the inferior patellar pole may be sufficient in managing even recalcitrant cases of PT.

However, this calls attention to the fact that most studies did not identify the presence or absence of PPTT or describe the size and thickness of the PPTT if present. Golman et al demonstrated that 56 out of 85 patients (65.88%) evaluated by MRI for suspected patellar tendon pathology and confirmed to have PT were found to also have a PPTT. Thus, the heterogeneity in baseline PT severity across the included studies limits the overall comparisons between each surgical technique. Future research should use objective classifications such as the Popkin-Golman system to objectively characterize the PT severity within their patient cohorts to ultimately determine the ideal treatments for differing severities of PT. For example, it is possible that if evaluating only Popkin-Golman grade 4 injuries (ie, PPTT with >50% of tendon thickness), simple débridement may lead to failure or rupture at an unacceptable rate resultantly supporting repair in these cases.

However, this systematic review has several limitations including the level of evidence available, heterogeneity among study design and data reporting among included studies, and lack of robust data regarding risks, complications, and revision surgery rates in each cohort. Although the average Modified Coleman Methodology Score was 80.13 (range 63 to 92) indicating that study reporting was very stringent overall, this review included only 2 level I, prospective, randomized control trials and 13 level IV studies (7 retrospective case series, six prospective case series). Studies in this review included a variety of arthroscopic and open procedures, outcome measures used, durations of follow-up, and athletes at different preinjury levels of competition. As such, the authors were unable to obtain a sufficient sample size to perform a meta-analysis comparing individual surgical procedures. The authors also did not specifically review complications following surgical treatment of PPTT or rehabilitation protocols before return to sport. As such, higher-quality studies are needed to further assess the optimal surgical approach to these injuries. Further areas of review include those procedures using suture anchors, direct suture repair, and autograft augmentation techniques that were largely not included in this review but may prove particularly beneficial if simple débridement techniques contribute to increased risk of postoperative patellar tendon rupture.^31,38

Conclusion

Historically, PT has been a challenging condition to treat, with unclear indications as to which patients would benefit from surgery versus nonsurgical management. New classification systems have been developed that may help guide physicians in deciding the patients to be treated surgically and the procedure most ideal for any given pathology. When surgery is indicated for patients with recalcitrant PT, there are several surgical techniques available. This review identified surgical techniques of varying invasiveness with great heterogeneity in design and technique that led to successful patient-reported outcomes and RTP rates. However, there is a dearth of high-quality comparative studies investigating newer techniques such as suture or autograft versus allograft augmentation. Future studies warrant prospective randomized trials and biomechanical studies for varying degrees of PT based on newer classification systems to optimize treatment based on the spectrum of PT pathology.