Abstract
Oxford unicompartmental knee arthroplasty (UKA) has been particularly prevalent because the concept of knee preservation is deeply rooted in people's minds. Mobile bearing UKA is a surgical type of UKA with considerable advantages. This note describes some surgical techniques, including patient position, surgical field exposure, selection of the size of the prosthesis, sagittal tibial osteotomy, placement of the femoral prosthesis and gap balance, to assist surgeons with less experience in performing these operations successfully. The techniques described in this note have been used in over 500 Oxford UKA cases, and nearly 95% patients achieved good prosthesis position and satisfactory postoperative outcome. We hope that the empirical summaries from numerous cases will help surgeons to learn Oxford UKA quickly and effectively, driving the spread of the technique and benefiting more patients.
Keywords: Mobile bearing, Oxford UKA, Prosthesis, Surgical techniques
This note describes some surgical techniques, including patient position, surgical field exposure, selection of the size of the prosthesis, sagittal tibial osteotomy, placement of the femoral prosthesis and gap balance, to assist surgeons with less experience in performing these operations successfully.
Introduction
Studies have shown that 250 million people suffer from osteoarthritis (OA) as a result of an aging and obese population worldwide, and nearly 85% of patients suffer from knee osteoarthritis, placing a heavy burden on the national healthcare system. 1 Knee OA patients could be treated according to their symptoms and progression of the disease with accurate therapies, both nonoperative and operative treatments. End‐stage patients without alleviation after a series of medical treatment methods are recommended for surgery. 2 , 3 Most patients received total knee arthroplasty (TKA), a well‐established and widely accepted surgical procedure. 4 However, after TKA, there is still a quite proportion of unsatisfied patients, which is reportedly related to the indication. 5 Previous studies suggested that most patients with knee osteoarthritis have predominantly unicompartmental medial lesions, which may make them more suitable for unicompartmental knee arthroplasty (UKA) rather than TKA. 6 Furthermore, the indications and contraindications for UKA surgery are changing as UKA surgical techniques continuing to improve and a deeper understanding of Oxford UKA emerges. 7 The changes in indications and contraindications are listed in Table 1. Many studies have demonstrated that UKA is associated with certain advantages, such as shorter stays in the hospital, fewer complications, better postoperative function and quicker recovery. 8 , 9 UKA includes two prosthesis bearing designs—fixed‐bearing (FB) and mobile‐bearing (MB)—both with certain advantages and disadvantages. The FB is accepted by most surgeons due to its low dislocation rate and the simplicity of the procedure. The higher risk of accelerated polyethylene wearing and patellar arthritis are the primary disadvantages of this design. 10 With the MB design, better knee joint kinematics can be restored, polyethylene wear can be reduced, and tibial osteotomies can be minimized. However, the risk of MB dislocation and long learning curve are concerning to many surgeons. 11 , 12 Accurate positioning of the prosthesis during surgery will markedly reduce the risk of dislocation, thus maximizing the benefits of MB. 13 In this study, we describe some surgical techniques for Oxford UKA to help surgeons achieve better clinical outcomes and reduce postoperative complications.
TABLE 1.
Indications and contraindications of Oxford unicompartmental knee arthroplasty.
| Kozinn & Scott (Classic in 1989) | (Newly in 1996) | ||
|---|---|---|---|
| Indications | Contraindications | Indications | Contraindications |
| Age >60 years | Diagnosis of inflammatory arthritis | Anterior medial osteoarthritis and SNOK | Diagnosis of inflammatory arthritis |
| Weight <82 kg | Patient age less than 60 years | Young and obese | Deficient ACL |
| Flexion contracture <5°, inversion deformity <10° | High patient activity level | Patellar arthritis | Direct contact of the medial tibiofemur |
| Normal with cruciate ligament, lateral collateral ligament, lateral meniscus | Pain at rest (which could indicate an inflammatory component to the arthropathy) | Flexion contracture <15°, inversion deformity <10° | Hardly restoring inversion deformity and so on |
| Chondrodysplasia of the interpatellar compartment <II | Patellofemoral pain | Not performing HTO | Flexion contracture>15° |
| Intact cartilage of lateral compartment | Intact cartilage of lateral compartment | Flexion range in anesthesia <100° | |
| Not performing HTO | Normal anterior cruciate ligament | ||
| No inflammatory and infectious arthritis | No inflammatory and infectious arthritis | ||
Note: This table is from Kozinn and Scott. 21
Abbreviation: ACL, anterior cruciate ligament.
Technique Note
Standard Patient Position
Standard patient positioning is the first step to performing a successful operation and involves flexion of the hip at 40°, abduction at 30°, and flexion of the knee at 110°, preserving the natural sagging of the lower limb. The lead surgeon should modulate the limb to determine an accurate measurement of ligament tension intraoperatively (Figure 1A–C).
FIGURE 1.
(A) shows flexion of hip at 40° and abduction of hip at 30°. (B) shows flexion of the knee at 110°. (C) shows natural sagging of the lower limb.
Exposure
An incision is then made from the medial aspect of the patella to the medial edge of the tubercle of the tibia, exposing the alar ligament and removing it to provide a clear view of the knee joint (Figure 2A). To eliminate osteophytes, certain key issues must be considered. (1) The osteophyte located on the medial condyle margin of the femur should be removed using a pair of rongeur forceps from the top down, which can help determine the boundary between normal bone and osteophytes, and reduce bone loss due to inappropriate operation (Figure 2B). Osteophytes in the medial and posterior of the plateau should not be removed with a bone knife or rongeur to avoid damaging the medial collateral ligament (MCL). Care should be taken to remove the tibial plateau to which the osteophyte is attached after the tibial osteotomy is complete. (2) Intercondylar osteophytes that damage the anterior cruciate ligament (ACL) must be removed (Figure 2C). (3) There is a specific pathological change in which osteophytes are located in both the medial tibial plateau and femoral condyle; this change is called the “bow‐arrow effect,” whose osteophytes should be completely removed before tibial osteotomy and intentionally reducing tibial osteotomy (Figure 2D,E).
FIGURE 2.
(A) the red arrow shows alar ligament. (B) illustrates using a rongeur from the top down to clear osteophytes. (C) the red arrow shows intercondylar osteophytes, which can damage the anterior cruciate ligament (ACL). (D, E) the red arrows shows medial osteophytes owing to wearing and tearing of the articular cartilage, then medial collateral ligament (MCL) is tighter, leading varus of lower limb force line, and we call it the “bow–arrow effect.”
Selective Right Size of Prosthesis
Two standard methods were used to help us identify the size of the prosthesis. (1) Using a measuring spoon to judge size, the distance to the loading surface of the femur was 2–3 mm, freely rotating 20–30° (Figure 3A–D). (2) Comparison of the prostheses with tibial plateaus from osteotomy and referring to Table 2 for size selection (Figure 3E–H).
FIGURE 3.
(A) illustrates the distance of measuring spoon to the loading surface with 2–3 mm. (B–D) show measuring spoon can freely rotation. (E–H) illustrate tibial plateaus from osteotomy compares with prostheses in different angles for right size selection.
TABLE 2.
Reference criteria for selecting the correct size.
| Female | Male | ||||
|---|---|---|---|---|---|
| Height | Femur | Relevant tibia | Height | Femur | Relevant tibia |
| <60 inch | Minimum | AA, A, B | <63 inch | Small | A, B, C |
| <155 cm | <160 cm | ||||
| <61–65 inch | Small | A, B, C | <63–67 inch | Middle | C, D |
| <155–165 cm | <160–170 cm | ||||
| <66–69 inch | Middle | C, D | <67–73 inch | Large | E, F |
| <165–175 cm | <170–185 cm | ||||
| >69 inch | Large | E | >73 inch | Maximum | F |
| >175 cm | >185 cm | ||||
Note: This table is from Goodfellow et al. 22
Sagittal Tibial Osteotomy
Sagittal bone cuts of the tibia are the first key point for the entire operation. We note five ways to ensure the position and direction of the osteotomy. (1) Passing the midpoint of the medial tibial intercondylar crest pointing toward the anterior superior iliac spine (Figure 4A). (2) Passing the midpoint of the medial tibial intercondylar crest and make a line with internal rotation of 5–10° compared with the central nail fixed in the tibial osteotomy baffle (Figure 4B). (3) The intersection point of the vertical line from the lateral edge of the medial femoral condyle to the tibia was passed toward the anterior superior iliac spine (Figure 4C). (4) Passing the midpoint of the medial tibial intercondylar crest pointing, inserting with the thinnest bone cutter along the channel between the lateral edge of the medial femoral condyle and the medial intercondylar crest of the tibia (Figure 4D). Making it insert smoothly is the right direction of osteotomy. (5) Parallel to the intramedullary positioning bar (Figure 4E).
FIGURE 4.
(A) shows that the red circle represents midpoint of the medial tibial intercondylar crest, and the red arrow illustrates direction of the osteotomy toward the anterior superior iliac spine. (B) illustrates that the green line represents central nail of the tibial osteotomy baffle, the red arrow represents direction of the osteotomy with internal rotation of 5–10° compared with green line. (C) shows that the red line represents vertical line from the lateral edge of the medial femoral condyle, the intersection pointing of the line on the tibia is passed, and the red arrow represents the direction of the osteotomy, toward anterior superior iliac spine. (D) shows that the black line represents medial femoral condyle, and the green line represents the medial intercondylar crest of the tibia. The red arrow represents proper channel between them, which can make the thinnest bone cutter insert smoothly. Meanwhile the red arrow is the right direction of osteotomy. (E) shows that the red line represents intramedullary positioning bar, and the green line represents the direction of the osteotomy paralleled to the red line when looking down.
Femoral Prosthesis Position
The position and orientation of the femoral borehole is the second key point for the entire operation: (1) The intramedullary locating rod entry point is 1 cm higher and 0.5 cm to the side compared with the outside margin of the medial femoral condyle (Figure 5A). The rod is also inserted parallel to the longitudinal axis of the femur (Figure 5B). (2) Proper bearing thickness is inserted to restore satisfying tension of the MCL. Then, a vertical line was accurately drawn in the center of the medial femoral condyle, which was parallel to the primary rod tibial osteotomy baffle (Figure 5C,D). Then, 6‐ and 4‐mm holes were made along this line. (3) The orientations of the 6‐ and 4‐mm holes should be parallel to the plane consisting of the indicating rod and primary rod of the tibial osteotomy baffle (Figure 5E,F).
FIGURE 5.
(A) illustrates location of intramedullary location rod entry point, with 1 cm higher and 0.5 cm to the side compared with the outside margin of the medial femoral condyle. (B) shows that the red line represents the longitudinal axis of the femur, and the black line represents orientation of intramedullary locating rod paralleled to the red line. (C, D) show two green lines represent margin of medial femoral condyle, and the vertical line was in the central of medial femoral condyle paralleling primary rod tibial osteotomy baffle. (E) shows that purple line represents primary rod of the tibial osteotomy baffle, green line representing indicating rod. The red plane consists of green and purple line, which paralleled to the 6‐ and 4‐mm holes. (F) shows intraoperative imagine, and the red arrow represents direction of holes paralleled to the red plane.
Gap Balance
There are three situations with a gap balance: (1) Removing more tibia is suitable for tight gaps both flexion and extension, while the loose gap could add bearing thickness. (2) Increased grinding of the distal femur can improve extension gap tension. (3) Partially distal femoral cement should be retained, or the prosthesis size should be changed to improve the lax extension gap.
Postoperative Outcomes
The standard radiological outcomes included the following aspects. Tibial implant compositions, including the baseplate, lateral wall and keel, all have no incline on the anterior–posterior film. Lateral imaging revealed a complete overlap of the medial and lateral femoral condyles (Figure 6A,B). The medial edge of the tibial prosthesis must completely cover the medial bone cortex or be suspended by 1–2 mm. The posterior margin of the tibial prosthesis completely covers the posterior bony cortex. The distance between the bearing and the lateral wall of the tibia is 1–2 mm. The tibial prosthesis has 7 degrees of posterior slope and 0–3 degrees of inversion. The femoral prosthesis has 10 degrees of flexion, 5 degrees of varus and valgus, and 10 degrees of internal and external rotation.
FIGURE 6.
(A, B) are standard radiological outcomes with anterior–posterior and lateral imaging respectively.
Discussion
Main Findings
UKA, a minimally invasive treatment therapy, has become prevalent with the development of technology for local knee arthritis. 14 Considering Oxford UKA advantages in rebuilding knee kinematics and decreasing bearing wear, the introduction of this technique will benefit many patients. 15 , 16 In fact, this technical note is a refinement and complement of the currently popular Oxford UKA tutorial and fully highlights our experience. First, we summarized the five methods to sagittal tibial osteotomy, using two or more to check each other to increase the accuracy of osteotomy. Second, we performed three‐step for accurate femoral prosthesis placement. Last, we first proposed the “bow‐arrow effect” and described how to avoid such traps.
Experience Sharing
This note provides some intraoperative surgical techniques that aim to assist surgeons in passing study‐curvy as soon as possible. (1) Standard patient position: a high degree of abduction and adduction of the limb will lead to external and internal rotation of the femur, respectively, influencing intraoperative MCL tension measurements. (2) Exposure: intercondylar osteophytes should be partly preserved to maintain joint stability for insufficient ACLs damaged by osteophytes. Wear and tear of the articular cartilage are the main causes of internal derangement of the knee, after which the growth of osteophytes appears to maintain the stability of the whole joint. At late times, as shown in Figure 2D, significant osteophytes develop on both the medial femoral condyle and the medial edge of the tibial plateau, which in long term results in poor elasticity of the medial collateral ligament. After the removal of the medial knee osteophyte, even the thickest spacer may not restore normal medial collateral ligament tension if a conventional tibial osteotomy is performed, leading to failure of the entire procedure. Our aim in proposing the “bow‐arrow effect,” as a graphic illustration, is to avoid surgical traps in specific pathological condition, and surgeons should think about reducing the amount of tibial osteotomy to restore the medial collateral ligament tension. (3) Sagittal tibial osteotomy: as we showed in the above article, five ways of sagittal tibial osteotomy concluded by our experiences can help new surgeons handle different situations in operation. What is more, the tibial osteotomy component could be fitted well with the medial bone surface (Figure S1), achieving sufficient tibial osteotomy varus. However, each of these five methods has its limitations. The first way is fairly routine but prone to visual errors in patients with narrow ACL footprint areas. The second relies heavily on the surgeon's experience and requires that the tibial osteotomy baffle be properly positioned. The third is used when the development of the medial femoral condyle is not significantly deformed. The fourth method relies on the surgeon's personal feelings and may produce some errors. The fifth is relatively practical, but requires the intramedullary bar to be accurately positioned. We have summarized the five methods because using one alone is prone to error, and using two or more to check each other increases the accuracy of osteotomy. We usually combine the second, third, and fifth methods to evaluate the accuracy of osteotomy. (4) Protection of MCL: another significant component of knee, medial collateral ligament (MCL), is easily ignored by inexperience surgeons owing to its simple structure. It is essential to ensure the integrity of the MCL throughout the procedure, which is the lifeline of the entire operation. 17 Releasing MCL is the one of the most important reasons causing mobile bearing dislocation in short time and lateral compartment damage in long time. We are convinced that nothing should be done to the MCL except to protect it throughout the process. Once the MCL is damaged, the operation fails. When we find a loose tension in the MCL, we should use a thicker spacer to restore balance rather than tighten the medial compartment. Of course, if equilibrium is not achieved with the thickest spacers, the only alternative is to fill the knee with bone cement or a revision via TKA. 18 (5) Femoral prosthesis position: the drawing line on the femur should be in the center of the medial femoral condyle, parallel to the primary rod tibial osteotomy baffle, to avoid excessive internal and external rotation of the femoral prosthesis. The risk of bearing dislocation increases in the internal rotation situation, and the femoral prosthesis impinges on the medial tibial intercondylar crest and lateral wall of the tibial prosthesis due to the external rotation prothesis (Figure 7A–C). The projection of the axis of the 6 mm hole on the coronal plane is parallel to the red plane, which avoids valgus or varus deformities of the femoral prosthesis. Valgus deformities of the femoral component will add more impingement to the lateral wall of the tibial prothesis and medial tibial intercondylar crest, while varus deformities of the femoral implant will cause a higher risk of prosthesis dislocation (Figure 8A–C). 19 (6) Gap balance: the flexion and extension gaps should be balanced, and if the gap cannot be balanced, a suitable tightening of the flexion gap with a tolerance of 0.5 cm should be considered. Excessive grinding of the distal femur causes laxity of the knee joint when extended. (7) Postoperative outcomes: in fact, if we make full use of the methods we have presented in this technical note, the possibility of unsatisfactory osteotomy is extremely slight. Ten cases were randomly selected to show proper placement of the prosthesis and satisfactory results using our surgical techniques (Figure 9A–J). Meanwhile, we showed postoperative MPTA of six patients on full‐length lower limb radiographs (S. Figure 2). According to the literature, the patients' satisfaction with standard Oxford UKA is 82.6%, while achieving nearly 95% satisfaction after using our technique notes. 20 The comparison of the pre‐ and post‐surgery Barthel and Hospital for Special Surgery (HSS) scores is presented in Table S1. Sharing our experience is a great help of reducing intraoperative errors, placing the prosthesis more precisely, and improving postoperative outcoming.
FIGURE 7.
(A) shows proper prosthetic placement. (B) shows internal rotation of femoral prothesis. (C) shows external rotation of femoral prothesis.
FIGURE 8.
(A) shows satisfactory femoral prothesis. (B) shows varus deformities of femoral component. (C) shows valgus deformities of the femoral implant.
FIGURE 9.
(A–J) ten cases were randomly selected to show proper placement of the prosthesis and satisfactory results.
Strengths and Limitations
This technique note has been applied to over 500 patients with excellent results and deserves to be promoted. However, some limitations should be noted. (1) It is difficult to memorize considerable intra‐operative details and gain a deeper understanding of the mechanism. (2) Unskilled use of these techniques can increase operation time. (3) Testing and refining these techniques will take more cases.
Conclusion
In conclusion, this technical note contains our understanding and thoughts on Oxford UKA, and we hope that the empirical summaries from numerous cases will help surgeons to learn Oxford UKA quickly and effectively, driving the spread of the technique and benefiting more patients.
Author Contributions
Peng Zhang, Jiaxiang Bai, and Jing Wang: writing—original draft preparation and data curation. Chen Zhu: conceptualization and methodology. Wei Zhou: conceptualization, methodology, writing—reviewing and editing.
Funding Information
This note did not receive any specific grant from funding agencies in the public, commercial, or not‐for‐profit sectors.
Conflict of Interest Statement
We declare that we have no financial or other conflicts of interest in relation to this research and its publication.
Ethical Approval
This study has been granted ethical approval by the ethics committee of the First Affiliated Hospital of USTC under reference number NO202208‐010.
Supporting information
Data S1. Supporting Information.
Acknowledgment
We are grateful to Dr. Ruixiang Ma for technical guidance.
Peng Zhang, Jiaxiang Bai and Jing Wang contributed equally to this study.
Contributor Information
Chen Zhu, Email: zhuchena@ustc.edu.cn.
Wei Zhou, Email: 734366239@qq.com.
REFERENCES
- 1. Hunter DJ, Bierma‐Zeinstra S. Osteoarthritis. Lancet. 2019;393(10182):1745–59. 10.1016/S0140-6736(19)30417-9 [DOI] [PubMed] [Google Scholar]
- 2. Katz JN, Arant KR, Loeser RF. Diagnosis and treatment of hip and knee osteoarthritis: a review. JAMA. 2021;325(6):568–78. 10.1001/jama.2020.22171 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Flury A, Weigelt L, Camenzind RS, Fritz B, Hasler J, Baumgaertner B, et al. Total and unicondylar knee arthroplasty are equivalent treatment options in end‐stage spontaneous osteonecrosis of the knee, and the size of the lesion has no influence on the results. Knee Surg Sports Traumatol Arthrosc. 2021;29(10):3254–61. 10.1007/s00167-020-06132-z [DOI] [PubMed] [Google Scholar]
- 4. Hawker GA, Bohm E, Dunbar MJ, Jones CA, Noseworthy T, Marshall DA, et al. The effect of patient age and surgical appropriateness and their influence on surgeon recommendations for primary TKA: a cross‐sectional study of 2,037 patients. J Bone Joint Surg Am. 2022;104(8):700–8. 10.2106/JBJS.21.00597 [DOI] [PubMed] [Google Scholar]
- 5. Tille E, Beyer F, Auerbach K, Tinius M, Lützner J. Better short‐term function after unicompartmental compared to total knee arthroplasty. BMC Musculoskelet Disord. 2021;22(1):326. 10.1186/s12891-021-04185-w [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Springer B, Boettner F. Treatment of Unicompartmental cartilage defects of the knee with Unicompartmental knee arthroplasty, patellofemoral partial knee arthroplasty or focal resurfacing. Life. 2021;11(5):394. 10.3390/life11050394 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. Mikkelsen M, Price A, Pedersen AB, Gromov K, Troelsen A. Optimized medial unicompartmental knee arthroplasty outcome: learning from 20 years of propensity score matched registry data. Acta Orthop. 2022;93:390–6. 10.2340/17453674.2022.2265 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Liddle AD, Judge A, Pandit H, Murray DW. Adverse outcomes after total and unicompartmental knee replacement in 101,330 matched patients: a study of data from the National Joint Registry for England and Wales. Lancet Lond Engl. 2014;384(9952):1437–45. 10.1016/S0140-6736(14)60419-0 [DOI] [PubMed] [Google Scholar]
- 9. Kahan ME, Chen Z, Angerett NR, Sax OC, Bains SS, Assayag MJ, et al. Unicompartmental knee arthroplasty has lower infection, conversion, and complication rates compared to high tibial osteotomy. J Knee Surg. 2022;35(14):1518–23. 10.1055/s-0042-1757597 [DOI] [PubMed] [Google Scholar]
- 10. Hariri M, Hauer G, Smolle M, Sadoghi P, Leithner A, Panzram B, et al. Mobile bearing versus fixed bearing medial unicompartmental knee replacement: an independent two center matched‐pairs analysis. Arch Orthop Trauma Surg. 2022;143:3383–9. 10.1007/s00402-022-04629-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. Ghosh P, Mohammad HR, Martin B, Campi S, Murray DW, Mellon SJ. Low polyethylene creep and wear following mobile‐bearing unicompartmental knee replacement. Knee Surg Sports Traumatol Arthrosc. 2021;29(10):3433–42. 10.1007/s00167-020-06243-7 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Sun X, Liu P, Lu F, Wang W, Guo W, Zhang Q. Bearing dislocation of mobile bearing unicompartmental knee arthroplasty in east Asian countries: a systematic review with meta‐analysis. J Orthop Surg. 2021;16(1):28. 10.1186/s13018-020-02190-8 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13. Tay ML, Monk AP, Frampton CM, Hooper GJ, Young SW. A comparison of clinical thresholds for revision following total and unicompartmental knee arthroplasty. Bone Joint J. 2023;105‐B(3):269–76. 10.1302/0301-620X.105B3.BJJ-2022-0872.R2 [DOI] [PubMed] [Google Scholar]
- 14. Jennings JM, Kleeman‐Forsthuber LT, Bolognesi MP. Medial Unicompartmental arthroplasty of the knee. J Am Acad Orthop Surg. 2019;27(5):166–76. 10.5435/JAAOS-D-17-00690 [DOI] [PubMed] [Google Scholar]
- 15. Savov P, Tuecking L‐R, Windhagen H, Calliess T, Ettinger M. Robotics improves alignment accuracy and reduces early revision rates for UKA in the hands of low‐volume UKA surgeons. Arch Orthop Trauma Surg. 2021;141(12):2139–46. 10.1007/s00402-021-04114-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Ekhtiari S, Bozzo A, Madden K, Winemaker MJ, Adili A, Wood TJ. Unicompartmental knee arthroplasty: survivorship and risk factors for revision: a population‐based cohort study with minimum 10‐year follow‐up. J Bone Joint Surg. 2021;103(23):2170–6. 10.2106/JBJS.21.00346 [DOI] [PubMed] [Google Scholar]
- 17. Wierer G, Milinkovic D, Robinson JR, Raschke MJ, Weiler A, Fink C, et al. The superficial medial collateral ligament is the major restraint to anteromedial instability of the knee. Knee Surg Sports Traumatol Arthrosc. 2021;29(2):405–16. 10.1007/s00167-020-05947-0 [DOI] [PubMed] [Google Scholar]
- 18. Walter N, Weber J, Kerschbaum M, Lau E, Kurtz SM, Alt V, et al. Revision arthroplasty after unicompartimental knee arthroplasty. J Orthop Surg. 2021;16(1):666. 10.1186/s13018-021-02767-x [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Kwon HM, Kang K‐T, Kim JH, Park KK. Medial unicompartmental knee arthroplasty to patients with a ligamentous deficiency can cause biomechanically poor outcomes. Knee Surg Sports Traumatol Arthrosc. 2020;28(9):2846–53. 10.1007/s00167-019-05636-7 [DOI] [PubMed] [Google Scholar]
- 20. Baryeh K, Maillot C, Gummaraju A, Rivière C. Disappointing relationship between functional performance and patient satisfaction of UKA patients: a cross sectional study. Orthop Traumatol Surg Res. 2021;107(3):102865. 10.1016/j.otsr.2021.102865 [DOI] [PubMed] [Google Scholar]
- 21.Kozinn SC, Scott R. Unicondylar knee arthroplasty. J Bone Joint Surg Am. 1989;71(1):145‐50. PMID: 2643607. [PubMed] [Google Scholar]
- 22.Goodfellow J, O’Connor J, Dodd C, Murray D. Unicompartmental Arthroplasty with The Oxford Knee. Oxford: Goodfellow Publishers; 2011. [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data S1. Supporting Information.