St Georg Sled medial unicompartmental arthroplasty: survivorship analysis and function at 20 years follow up.

PURPOSE: The peri-operative and short-term benefits of unicompartmental knee arthroplasty (UKA) are well supported in the literature. However, there remains concern regarding the higher revision rate when compared with total knee replacement. This manuscript reports the functional outcome and survivorship of a large series of fixed bearing, medial unicompartmental replacements (St Georg Sled), with a minimum of 20 years follow-up. METHODS: Between 1974 and 1994, 399 patients (496 knees) underwent a medial fixed-bearing UKA. Prospective data were collected pre-operatively and at regular intervals post-operatively using the Bristol Knee Score (BKS), Oxford Knee (OKS) and Western Ontario MacMaster (WOMAC) scores. Kaplan-Meier survival analysis was used to determine survivorship, with revision or need for revision as end point, and differences assessed using Mantel-Cox log rank test. RESULTS: Functional knee scores improved post-operatively, but demonstrated a slight decline from 10 years of follow-up onwards. Survivorship is estimated as 86% at 10 years, 80% at 15 years, and 78% at 20 years. Sixty knees were revised, with progression of disease in another compartment the commonest reason. Eighty eight percent were revised using a primary prosthesis. For patients over the age of 65 years at the time of index procedure, 93% died with a functioning prosthesis in situ. CONCLUSION: Medial UKA demonstrates good long-term function and survivorship, and represents an excellent surgical option for patients aged over 65 years of age, where few patients will require a revision procedure. LEVEL OF EVIDENCE: IV.

Patient Reported Kneeling Ability in Fixed and Mobile Bearing Knee Arthroplasty.

Kneeling is an important function of the knee joint required for many daily activities. Bearing type is thought to influence functional outcome following UKA and TKA. Self-reported kneeling ability was recorded in 471 UKA and 206 TKA patients with fixed or mobile bearing implants. Kneeling ability was recorded from the Oxford Knee Score question 7. The self-reported ability to kneel was similar in patients with fixed and mobile bearing UKA implants following surgery. In TKA, greater proportions of patients were able to kneel in the fixed compared to the mobile bearing groups up to two years after surgery indicating that self-reported kneeling ability is enhanced in fixed compared to mobile bearing TKA.

Single-stage repair of displaced bucket-handle meniscal tears with anterior cruciate ligament reconstruction leads to good meniscal survivorship : a retrospective cohort study.

AIMS: The best surgical strategy for the management of displaced bucket-handle (BH) meniscal tears in an anterior cruciate ligament (ACL)-deficient knee is unclear. Combining meniscal repair with ACL reconstruction (ACLR) is thought to improve meniscal healing rates; however, patients with displaced BH meniscal tears may lack extension. This leads some to advocate staged surgery to avoid postoperative stiffness and loss of range of motion (ROM) following ACLR. METHODS: We reviewed the data for a consecutive series of 88 patients (mean age 27.1 years (15 to 49); 65 male (74%) and 23 female (26%)) who underwent single-stage repair of a displaced BH meniscal tear (67 medial (76%) and 21 lateral (24%)) with concomitant hamstring autograft ACLR. The patient-reported outcome measures (PROMs) EuroQol visual analogue scale (EQ-VAS), EuroQol five-dimension health questionnaire (EQ-5D), Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee score (IKDC), and Tegner score were recorded at final follow-up. A Kaplan-Meier survival analysis was performed to estimate meniscal repair survivorship. Analyses were performed with different cut-offs for meniscal and ACL injury-to-surgery time (within three weeks, three to ten weeks, and more than ten weeks). RESULTS: Meniscal repair survivorship at a median final follow-up of 55 months (interquartile range (IQR) 24 to 91) was 82% (95% confidence interval 70 to 89). A total of 13 meniscus repairs failed (12 requiring meniscectomy and one requiring a further meniscal repair). At final follow-up, median PROMs were: EQ-VAS 85 (IQR 75 to 90), EQ-5D Index 0.84 (IQR 0.74 to 1.00), KOOS Pain 89 (IQR 80 to 94), KOOS Symptoms 82 (IQR 71 to 93), KOOS Activities of Daily Living 97 (IQR 91 to 100), KOOS Sport and Recreation 80 (IQR 65 to 90), KOOS Quality of Life 69 (IQR 53 to 86), IKDC 82.8 (IQR 67.8 to 90.8), and Tegner 6 (IQR 4 to 7). Two patients underwent revision ACLR following further injuries. One patient had an arthroscopic washout for infection at 11 days post-BH meniscal repair/ACLR. Four patients (4.5%) required a further procedure for stiffness, reduced ROM, and pain, and all were operated on within three weeks of meniscal injury. There was no difference in the interval between meniscal injury and surgery between repairs that failed and those that survived. CONCLUSION: These data suggest that concomitant ACLR with repair of displaced BH meniscal tears, even if they have been displaced for some time, appears to afford satisfactory PROMs and good survivorship. Repairs within three weeks of meniscal injury may be associated with higher rates of postoperative reintervention for stiffness. Cite this article: Bone Joint J 2022;104-B(6):680-686.

Fixed bearing, all-polyethylene tibia, lateral unicompartmental arthroplasty - A final outcome study with up to 28 year follow-up of a single implant.

BACKGROUND: Lateral unicompartmental arthroplasty (UKA) constitutes only 5-10% of all unicompartmental replacements performed. Whilst the short and medium term benefits are well documented, there remains concern regarding the higher revision rate when compared with total knee replacement. We report the long term clinical outcome and survivorship of a large series of lateral UKA. PATIENTS AND METHODS: Between 1974 and 1994, 71 patients (82 knees) underwent a lateral fixed-bearing St Georg Sled UKA. Prospective data was collected pre-operatively and at regular intervals post-operatively using the Bristol Knee Score (BKS), with later introduction of the Oxford Knee (OKS) and Western Ontario MacMaster (WOMAC) scores. Kaplan Meier survival analysis was used, with revision, or need for revision, as end point. 85% of the patients were female. No patients were lost to follow-up. RESULTS: Functional knee scores improved post-operatively up to 10 years, at which point they demonstrated a steady decline. Survivorship was 72% at 15 years, and 68% at 20 and 25 years. Nineteen knees were revised, with progression of disease in another compartment the commonest reason. There were two revisions due to implant fracture. In patients aged over 70 years at time of index procedure, 81% died with a functioning prosthesis in situ. CONCLUSION: This represents the longest follow-up of a large series of lateral UKA. Results of this early design of fixed bearing UKA demonstrate satisfactory long term survivorship. In elderly patients, further intervention is rarely required. More contemporary designs or techniques may show improved long term survivorship in time.

Minimum 10-year outcomes of a fixed bearing all-polyethylene unicompartmental knee arthroplasty used to treat medial osteoarthritis.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) accounts for 8.9% of knee arthroplasty procedures in England, Wales and Northern Ireland. Fixed bearing UKA designs have shown favourable survivorship in registries when compared with mobile bearings but some studies suggest poor survival of all-polyethylene fixed tibial bearings. This study analyses long-term follow-up of patients with a medial fixed all-polyethylene tibial bearing UKA and reports survivorship and 10-year clinical outcomes. METHODS: Data was collected prospectively for 214 medial unicompartmental all-polyethylene tibial bearing UKAs implanted in 184 patients at our tertiary referral centre between November 2002 and December 2007. The indication was osteoarthritis in all but one patient. Patient reported outcome scores were documented pre-operatively and at five, eight, 10 and 12 years of follow-up. The mean patient age was 70 years (range 41-87). RESULTS: Outcome and survivorship data were collected for 214 medial all-polyethylene tibial bearing UKAs. There were outcomes recorded for 83 UKAs with at least 10-year follow-up. Twenty-four patients underwent revision of their UKA at an average of 5.84 years after the primary procedure. Kaplan-Meier analysis demonstrated survivorship of 89.1% at 10 years and the OKS, AKSS and WOMAC patient reported outcomes remained significantly improved in comparison to preoperatively. For those 70 years or older, 10-year survivorship was 92.4%, compared to 85.0% for those under 70 years old. CONCLUSION: Medial fixed all-polyethylene tibial bearing UKA demonstrates acceptable long-term survivorship and patient outcomes. It appears to be a suitable option for the treatment of medial compartment OA, particularly in older patients.

Analysis Of The KLIC-score; An Outcome Predictor Tool For Prosthetic Joint Infections Treated With Debridement, Antibiotics And Implant Retention.

Background: Debridement, antibiotics and implant retention (DAIR) forms the primary treatment modality for early prosthetic joint infection (PJI). The KLIC score has been proposed as a risk stratification tool for use in predicting outcome of prosthetic knee infections. Our aim was to determine the accuracy of this scoring system at an independent tertiary PJI centre in a typical DAIR population. Methods: Between 2008 and 2015, patients with infected knee prostheses treated with DAIR were identified. The patient notes and blood tests were reviewed retrospectively and the 'KLIC-score' was calculated and correlated with outcome. The end point for early failure was defined as: 1) the need for unscheduled surgery, 2) infection-related death ≤12 months from debridement or 3) the need for suppressive antibiotic treatment. Results: 59 patients received DAIR procedures for knee PJI. Treatment was successful in 41 patients (69%) with early failure in 18 patients (31%). Patients deemed high-risk (KLIC-score ≥7) had notably higher failure rates (60%) than those scoring <7 (28%). No relationship can be drawn between KLIC-scores of <7 and failure rates. Conclusions: The KLIC-score applied retrospectively was able to predict patients with the highest risk of early failure but provides little information in patients with scores of <7.

The Journey patellofemoral joint arthroplasty: A minimum 5year follow-up study.

BACKGROUND: The Journey patellofemoral joint arthroplasty (PFA) was designed to improve patient outcomes following surgical management of patellofemoral joint osteoarthritis. It is based on the asymmetric trochlear geometry of the Genesis II total knee arthroplasty, with Oxinium components, to provide a reliable treatment option in an often young, high demand group of patients. METHODS: We report the minimum five year functional outcome and survivorship of the Journey PFA performed at our institution between October 2005 and September 2009. RESULTS: A total of 101 Journey PFAs were implanted in 83 patients, and we have complete outcomes for 90 implants (89%). There were 80 implants in female patients, and the mean age at time of surgery was 60years (26 to 86). The median Oxford Knee Score (0 to 48) improved from 18 to 30, and median Western Ontario and McMaster University Osteoarthritis Short Form Index (0 to 60) improved from 22 to 35. There were a total of 12 revisions, with mean time to revision 50months (10 to 99). CONCLUSIONS: The Journey PFA gives a good medium-term functional outcome with 88% survivorship at a mean of seven years. This is the largest study of Journey PFA in the literature, and it provides a reliable option for patients with isolated patellofemoral joint osteoarthritis when arthroplasty is considered.

Management of the exposed total knee prosthesis, a six-year review.

INTRODUCTION: An exposed knee prosthesis is a limb threatening condition. Our unit manages such cases according to a multidisciplinary orthoplastic protocol. Whilst early prosthetic joint infection with dehiscence may be managed by Debridement, Antibiotics and Implant Retention (DAIR) and soft tissue coverage, the majority of these cases are chronic and in our unit are managed by Debridement, Explantation, Antibiotics (spacer and systemic) and Flap (DEAF). PATIENTS AND METHODS: We report our experience of managing 17 of these challenging cases, 16 DEAFs and one DAIR and flap. Outcomes were assessed clinically and using the 36-item Short Form Health Survey (SF-36). RESULTS: The mean time from arthroplasty to presentation in our unit was 19months (range: 0.5-80). Whilst an open knee replacement is by definition 'infected', significant microbiological growth from deep tissue/fluid samples was only detected in 14 patients (82%). Five patients (29.4%) subsequently underwent an amputation. Of these five, three patients were extensor deficient at presentation. At follow-up, health-related quality of life scoring using the Short Form-36 demonstrated poor physical function and highlighted differences in emotional function and pain levels between patients whose limbs were salvaged and patients who underwent amputation. CONCLUSION: An exposed total knee prosthesis is a devastating complication, which despite our multidisciplinary salvage approach, has a high rate (5/17=29%) of amputation in this series. Quality of life in this patient group is poor irrespective of limb salvage. Salvage surgery was associated with worse pain, but better emotional profile than patients with an above knee amputation.

Fixed bearing lateral unicompartmental knee arthroplasty--short to midterm survivorship and knee scores for 101 prostheses.

BACKGROUND: Isolated unicompartmental knee arthritis is less common laterally than medially. Lateral unicompartmental knee arthroplasty (UKA) constitutes only 1% of all knee arthroplasty performed. Use of medial UKA is supported by several published series showing good long-term survivorship and patient satisfaction, in large patient cohorts. Results of lateral UKA however have been mixed. We present the short and mid-term survivorship and 5-year clinical outcome of 101 lateral UKAs using a single prosthesis. METHODS: Over a 9 year period, 100 patients who satisfied inclusion criteria underwent a lateral fixed-bearing unicompartmental arthroplasty. American Knee Society (AKSS), Oxford Knee (OKS) and modified Western Ontario McMaster Universities Arthritis Index (WOMAC) scores were completed preoperatively and at 1, 2 and 5 years postoperatively. Kaplan-Meier survival analysis was used to determine the 2-year and 5-year survivorship, using revision for any cause as end point. RESULTS: Survivorship was 98.7% and 95.5% at 2 and 5 years respectively. 1 knee was revised for subsidence of the tibial component and 1 knee for progression of medial compartment osteoarthritis. Of a possible 35 knees in situ at 5 year follow-up, 33 knees were fully scored. Median AKSS, OKS and modified WOMAC scores were 182, 41, and 16 respectively. CONCLUSIONS: The mid-term survivorship and outcome scores at 5-years suggest that lateral unicompartmental knee arthroplasty provides a valuable alternative to total joint replacement in selected patients with isolated lateral tibio-femoral arthritis at mid-term follow-up. Level II evidence.

The Posterior Condylar Offset Ratio.

INTRODUCTION: Posterior Condylar Offset is an area of interest in knee arthroplasty research and clinical outcome. The aim of the study is to define a quantifiable Posterior Condylar Offset Ratio, a normal value for this ratio and to confirm its reproducibility on pre-operative radiographs. METHOD: We propose a new Posterior Condylar Offset Ratio which is defined as the maximal thickness of the posterior condyle projecting posteriorly to a straight line drawn as the extension of the posterior femoral shaft cortex, divided by the maximal thickness of the posterior condyle projecting posterior to a straight line drawn as the extension of the anterior femoral shaft cortex on a true lateral radiograph of the distal quarter of the femur. We have measured this on 100 true lateral radiographs (50 females, 50 males, and mean age 65 years). RESULTS: The mean ratio was 0.44 (SD 0.02) and was shown to have good reproducibility (intra-observer error 0.899 and inter-observer error 0.882. The ratio was also very consistent between male and female patients (0.44 (SD 0.02) for the males and 0.45 (SD 0.02) for the females). Adjusting the ratio for reported posterior condyle articular cartilage thickness increased the ratio to 0.47 (SD 0.02). CONCLUSION: We suggest our Posterior Condylar Offset Ratio is a useful tool to aid further research in this area of knee arthroplasty and propose a normal value of 0.44 on radiographs and 0.47 on post-operative knee arthroplasty radiographs.

Functional outcomes after different types of knee arthroplasty: kneeling ability versus descending stairs.

BACKGROUND: Most patients do not kneel following knee replacement and many are of an age when it is not necessary. However, inability to kneel after knee surgery is a frequent cause of dissatisfaction and it is of paramount importance to patients from the East. There are very few studies of this function after knee replacement and none comparing different types of replacement. MATERIAL/METHODS: This study analyzes the kneeling and stair-descending abilities of patients following unicompartmental replacement (UKR), patellofemoral replacement (PFR), and total knee replacement (TKR). Data were prospectively collected on 253 knees (239 patients) that had undergone various arthroplastic procedures for osteoarthritis of the knee. Al1 patients completed the Oxford Knee Score Questionnaire preoperatively and 1 and 2 years postoperatively; thus grading their kneeling ability into 1 of 5 categories. RESULTS: Only 3% of patients could kneel pre-operatively, while 20% could manage stairs with ease. Post-operatively, 17% of patients could kneel, while 75% could manage stairs with little or no difficulty. CONCLUSIONS: Many patients remained unable to kneel after one year in all groups. Those who had undergone UKR appeared to perform better than those with TKR or PFR. None of the forms of arthroplasty used resulted in good kneeling ability, though arthroplasty improved this function. On the other hand, stair-descending ability showed a far better improvement. Further work is needed to clarify why patients are unable to kneel, but many factors are involved.