There is little published literature to support the claim that a successful total knee replacement (TKR) is predictive of future good outcomes on the contralateral side. The objective was to identify whether outcome from the first of staged TKRs could be used to predict the outcome of the contralateral TKR.

This was a retrospective cohort study of 1687 patients over a 25-year period undergoing staged bilateral TKRs in a UK arthroplasty centre. A control group of 1687 patients undergoing unilateral TKR with matched characteristics was identified. Primary outcomes were satisfaction and Knee Society Score (KSS) at one year.

Preoperative status was comparable for pain, ROM and KSS (mean 41, 45, 43±14). At one year follow up, dissatisfaction was similar for all groups (4% first of staged TKR, 4% second of staged TKR, 5% controls). If the first TKR had a good outcome, the relative risk of a contralateral bad outcome was 20% less than controls (95% CI 0.6–1.2). If the first TKR had a poor outcome, the risk of a second poor outcome was 4 times higher (95% CI 2.8–6.1), increasing from 6% to 27% (absolute risk).

Patients undergoing the second of staged TKRs with a previous good outcome are likely to do well in their second procedure (94 in 100 will go on to have a second good outcome). Of those with a previous poor outcome, 27 in 100 will have a second poor outcome. The trend was persistent despite correcting for gender, age, BMI, and diagnosis.

Abstract

Abstract

It is anecdotally thought that a good outcome from the first of staged total hip arthroplasties (THAs) is predictive of benefit on the contralateral side. The objective was to determine whether outcome from the first THA could be used to predict outcome from the second, contralateral THA.

A retrospective cohort study of consecutive patients undergoing staged THAs at a UK arthroplasty centre over 25-years (1995–2020). A control THA group was identified and matched for age, gender, BMI, implant and diagnosis. One-year patient-reported outcome data was available for 91% 1543/1700.

1700 patients who underwent staged THA were compared to 1700 matched controls. Preoperative status was comparable for pain, function, and modified Harris hip score (mHHS, mean 41 SD 13 for both groups).

At one year, there was a 2% dissatisfaction rate in all groups (first of staged THAs, second of staged THAs and controls). Groups were similar in terms of pain, function and mHHS (mean 88 SD 11 for all groups). For every 100 patients undergoing staged THAs, 87 had a bilateral good outcome (mHHS >70 both), 11 had unilateral poor outcome (mHHS >70 one, <70 other) and 2 had bilateral poor outcome (mHHS <70 both).

If the first THA had a good outcome, the relative risk of a bad outcome was 20% less than for controls (RR 0.8 95% CI 0.6–1.1). If the first THA had a poor outcome, the risk of a second poor outcome was 4.5 times higher (RR 4.5 95% CI 3.2–6.4), increasing from 6% to 29% (absolute risk).

Patients undergoing staged THAs with a good outcome from the first THA were less likely to have a bad outcome with the second. Risk of a poor outcome after a previous successful THA was 6% but rose to almost 30% with a previous poor outcome. This remained after correcting for patient variables including gender, age, BMI and diagnosis, indicating a potentially novel independent risk factor for poor outcome from staged THA.

Sub-acromial decompression surgery (SAD) has been widely used to treat shoulder impingement. Its validity has been questioned in multi-centric clinical trials and dissatisfaction rates can be high (35%). It is difficult to predict which patients will benefit operatively as research into predictive factors is limited. The study aim was to conduct a root-cause analysis of reasons for dissatisfaction in a cohort of operated patients.

All patients with SAD dissatisfaction in the local Upper Limb database between 2015-19 (n=74/296) formed our study cohort. Patients were scored on Oxford shoulder score (OSS), QuickDASH score, EQ-5D-3L (TTO+VAS) at weeks 26 and 52 post-operatively. Patients' clinical history, radiographs, consultation and operative notes were reviewed.

28% of patients were dissatisfied with surgery. Mean age =52.3±13.4 years with equal gender distribution. 87% were operated arthroscopically. 67% were in physically demanding occupations. There was a significant increase in OSS and QuickDASH at weeks 26 and 52 post-operatively (p<0.05), similar improvement was not noted in VAS pain score. Pain followed by stiffness were the main contributors of dissatisfaction. Multiple implicating factors were noted, the most common being acromio-clavicular joint arthritis (25.7%), suggesting concomitant pathologies as an additional cause for patient dissatisfaction.

This is the first study to evaluate reasons for dissatisfaction following SAD. We noted high rates (28%) of dissatisfaction and a predilection for those involved in physically demanding occupations. We recommend meticulous pre-operative workup to identify co-existing pathologies and appropriate pre-operative counselling to improve outcomes in selected patients needing SAD following failure of conservative management.

Unicompartmental knee osteoarthritis can be treated with either Total Knee Arthroplasty (TKA) or Unicompartmental Knee Arthroplasty (UKA) and controversy remains as to which treatment is best. UKA has been reported to offer a variety of advantages, however many still see it as a temporary procedure with higher revision rates.

We aimed to clarify the role of UKA and evaluate the long-term and revision outcomes. We retrospectively reviewed the pain, function and total Knee Society Score (KSS) for 602 UKA and 602 TKA in age and gender matched patients over ten years.

The total pre-operative KSS scores were not significantly different between UKA and TKA (42.67 vs 40.54 P=0.021). KSS (pain) was significantly better in the TKA group (44.39 vs 41.38 P= 0.007) at one year and at five years post-operatively (45.33 vs 43.12 P=0.004). There was no statistically significant difference for KSS (total) in TKA and UKA during the study period. 16.3% of UKA and 20.1% of TKA had a documented complication. 79 UKA (13%) and 36 TKA (6%) required revision surgery. Despite the higher revision rate, pre-operative KSS (total) before revision was not significantly different between UKA and TKA (42.94 vs 42.43 P=0.84). Performance for UKAs was inferior to TKAs in Kaplan-Meier cumulative survival analysis at 10 years (P<0.001).

Both UKA and TKA are viable treatment options for unicompartmental knee osteoarthritis, each with their own merits. UKA is associated with fewer complications whereas TKA provides better initial pain relief and is more durable and less likely to require revision.

Objectives

The primary stability of the cementless Oxford Unicompartmental Knee Replacement (OUKR) relies on interference fit (or press fit). Insufficient interference may cause implant loosening, whilst excessive interference could cause bone damage and fracture.

The aim of this study was to identify the optimal interference fit by measuring the force required to seat the tibial component of the cementless OUKR (push-in force) and the force required to remove the component (pull-out force).

The use of Birmingham hip resurfacing (BHR) remains controversial due to the increased revision rate in female patients. We compared the outcomes of BHR in female patients to an age matched total hip arthroplasty(THA) cohort. We reviewed the pain, function and total Harris Hip Scores(HHS), and Kaplan-Meir survivorship for BHR and THA cohorts from a prospective regional arthroplasty database.

There were 234 patients in each cohort, with mean age of 51 years. The BHR cohort had significantly better function and total HHS at all points of the 5-year study, but not for the post-operative pain score. The 5-year revision rate for the BHR cohort was significantly higher than the THA cohort (6.8% vs 3.4%, p=0.001). The main reason for revision in the BHR cohort was aseptic loosening (n=8), followed by metallosis (n=3). The 5-year Kaplan-Meier survivorship was 92.6% (95% CI±1.7%) and 96.4% (95% CI±1.3%) for the BHR and THA cohort (p=0.001).

BHR can give significantly better functional outcomes than THA. The vast majority of female patients were happy with BHR and did not need further surgery at the 5-year stage. This is somewhat at odds with the recent reputation of the procedure. The 10-year result of the same cohort is warranted to provide further data. Our study is not a recommendation to still offer BHR to female patients, but rather to inject a note of realism into the debate. There are implications for future implant development in that these results do validate resurfacing as a functionally valuable option for active patients.

Background

Metal on metal hip resurfacing has become popular worldwide for younger patients because of perceived advantages in function and ease of revision, due to bone conservation. Joint Registry data have shown increased risk of early failure, particularly in younger females. There have been few studies comparing the outcome of resurfacing to cemented total hip arthroplasty (THA).