Aims. Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used. Materials and Methods. A search of PubMed and Medline was performed in October 2018 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “knee”, and “surgery”. The criteria for inclusion was any study describing the use of robotic UKA and reporting implant positioning, ROM, function, and survival for clinical, cadaveric, or dry bone studies. Results. A total of 528 articles were initially identified from the databases and reference lists. Following full text screening, 38 studies that satisfied the inclusion criteria were included. In all, 20 studies reported on implant positioning, 18 on functional outcomes, 16 on survivorship, and six on ROM. The Mako (Stryker, Mahwah, New Jersey) robot was used in 32 studies (84%), the BlueBelt Navio (Blue Belt Technologies, Plymouth, Minnesota) in three (8%), the Sculptor RGA (Stanmore Implants, Borehamwood United Kingdom) in two (5%), and the Acrobot (The Acrobot Co. Ltd., London, United Kingdom) in one study (3%). The most commonly used implant was the Restoris MCK (Stryker). Nine studies (24%) did not report the implant that was used. The pooled survivorship at six years follow-up was 96%. However, when assessing survival according to implant design, survivorship of an inlay (all-polyethylene) tibial implant was 89%, whereas that of an onlay (metal-backed) implant was 97% at six years (odds ratio 3.66, 95% confidence interval 20.7 to 6.46, p < 0.001). Conclusion. There is little description of the choice of implant when reporting robotic-assisted UKA, which is essential when assessing survivorship, in the literature. Implant positioning with robotic-assisted UKA is more accurate and more reproducible than that performed manually and may offer better functional outcomes, but whether this translates into improved implant survival in the mid- to longer-term remains to be seen. Cite this article: Bone Joint J 2019;101-B:838–847

Aims. Patients with a deformity of the hindfoot present a particular challenge when performing total knee arthroplasty (TKA). The literature contains little information about the relationship between TKA and hindfoot alignment. This systematic review aimed to determine from both clinical and radiological studies whether TKA would alter a preoperative hindfoot deformity and whether the outcome of TKA is affected by the presence of a postoperative hindfoot deformity. Methods. A systematic literature search was performed in the databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of “total knee arthroplasty/replacement” combined with “hindfoot/ankle alignment”. Inclusion criteria were all English language studies analyzing the association between TKA and the alignment of the hindfoot, including the clinical or radiological outcomes. Exclusion criteria consisted of TKA performed with a concomitant extra-articular osteotomy and case reports or expert opinions. An assessment of quality was conducted using the modified Methodological Index for Non-Randomized Studies (MINORS). The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the PROSPERO database (CRD42019106980). Results. A total of 17 studies were found to be eligible for review. They included six prospective and ten retrospective studies, and one case-control study. The effects of TKA showed a clinical improvement in the hindfoot deformity in three studies, but did not if there was osteoarthritis (OA) of the ankle (one study) or a persistent deformity of the knee (one study). The radiological alignment of the hindfoot corrected in 11 studies, but did not in the presence of a rigid hindfoot varus deformity (in two studies). The effects of a hindfoot deformity on TKA included a clinical association with instability of the knee in one study, and a shift in the radiological weightbearing axis in two studies. The mean MINORS score was 9.4 out of 16 (7 to 12). Conclusion. TKA improves both the function and alignment of the hindfoot in patients with a preoperative deformity of the hindfoot. This may not apply if there is a persistent deformity of the knee, a rigid hindfoot varus deformity, or OA of the ankle. Moreover, a persistent deformity of the hindfoot may adversely affect the stability and longevity of a TKA. These findings should be interpreted with caution due to the moderate methodological quality of the studies which were included. Therefore, further prospective studies are needed in order to determine at which stage correction of a hindfoot deformity is required to optimize the outcome of a TKA. Cite this article: Bone Joint J 2021;103-B(1):87–97

We conducted a meta-analysis, including randomised controlled trials (RCTs) and cohort studies, to examine the effect of patient-specific instruments (PSI) on radiological outcomes after total knee replacement (TKR) including: mechanical axis alignment and malalignment of the femoral and tibial components in the coronal, sagittal and axial planes, at a threshold of > 3º from neutral. Relative risks (RR) for malalignment were determined for all studies and for RCTs and cohort studies separately.

Of 325 studies initially identified, 16 met the eligibility criteria, including eight RCTs and eight cohort studies. There was no significant difference in the likelihood of mechanical axis malalignment with PSI versus conventional TKR across all studies (RR = 0.84, p = 0.304), in the RCTs (RR = 1.14, p = 0.445) or in the cohort studies (RR = 0.70, p = 0.289). The results for the alignment of the tibial component were significantly worse using PSI TKR than conventional TKR in the coronal and sagittal planes (RR = 1.75, p = 0.028; and RR = 1.34, p = 0.019, respectively, on pooled analysis). PSI TKR showed a significant advantage over conventional TKR for alignment of the femoral component in the coronal plane (RR = 0.65, p = 0.028 on pooled analysis), but not in the sagittal plane (RR = 1.12, p = 0.437). Axial alignment of the tibial (p = 0.460) and femoral components (p = 0.127) was not significantly different.

We conclude that PSI does not improve the accuracy of alignment of the components in TKR compared with conventional instrumentation.

Cite this article: Bone Joint J 2014; 96-B:1052–61.

Mobile-bearing (MB) total knee replacement (TKR) was introduced to reduce the risk of aseptic loosening and wear of polyethylene inserts. However, no consistent clinical advantages of mobile- over fixed-bearing (FB) TKR have been found. In this study we evaluated whether mobile bearings have an advantage over fixed bearings with regard to revision rates and clinical outcome scores. Furthermore, we determined which modifying variables affected the outcome.

A systematic search of the literature was conducted to collect clinical trials comparing MB and FB in primary TKR. The primary outcomes were revision rates for any reason, aseptic loosening and wear. Secondary outcomes included range of movement, Knee Society score (KSS), Oxford knee score (OKS), Short-Form 12 (SF-12) score and radiological parameters. Meta-regression techniques were used to explore factors modifying the observed effect.

Our search yielded 1827 publications, of which 41 studies met our inclusion criteria, comprising over 6000 TKRs. Meta-analyses showed no clinically relevant differences in terms of revision rates, clinical outcome scores or patient-reported outcome measures between MB and FB TKRs. It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice.

Cite this article: Bone Joint J 2013;95-B:1209–16.

Objectives. This systematic review and meta-analysis was conducted to determine the mid- to long-term clinical outcomes for a medial-pivot total knee replacement (TKR) system. The objectives were to synthesise available survivorship, Knee Society Scores (KSS), and reasons for revision for this system. Methods. A systematic search was conducted of two online databases to identify sources of survivorship, KSS, and reasons for revision. Survivorship results were compared with values in the National Joint Registry of England, Wales, and Northern Ireland (NJR). Results. A total of eight studies that included data for 1146 TKRs performed in six countries satisfied the inclusion/exclusion criteria. Pooled component survivorship estimates were 99.2% (95% CI, 97.7 to 99.7) and 97.6% (95% CI, 95.8 to 98.6) at five and eight years, respectively. Survivorship was similar or better when compared with rates reported for all cemented TKRs combined in the NJR and was significantly better than some insert types at mid-term intervals. The weighted mean post-operative KSS was 87.9 (73.2 to 94.2), in the excellent range. Similar cumulative revision rates and KSS were reported at centres in the United States, Europe, and Asia. Conclusions. The subject system was associated with survivorship and KSS similar or better than that reported for other TKR systems. Cite this article: Bone Joint Res 2014;3:297–304

Total knee replacement (TKR) is an effective method of treating end-stage arthritis of the knee. It is not, however, a procedure without risk due to a number of factors, one of which is diabetes mellitus. The purpose of this study was to estimate the general prevalence of diabetes in patients about to undergo primary TKR and to determine whether diabetes mellitus adversely affects the outcome. We conducted a systematic review and meta-analysis according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. The Odds Ratio (OR) and mean difference (MD) were used to represent the estimate of risk of a specific outcome. Our results showed the prevalence of diabetes mellitus among patients undergoing TKR was 12.2%. Patients with diabetes mellitus had an increased risk of deep infection (OR = 1.61, 95% confidence interval (CI), 1.38 to 1.88), deep vein thrombosis (in Asia, OR = 2.57, 95% CI, 1.58 to 4.20), periprosthetic fracture (OR = 1.89, 95% CI, 1.04 to 3.45), aseptic loosening (OR = 9.36, 95% CI, 4.63 to 18.90), and a poorer Knee Society function subscore (MD = -5.86, 95% CI, -10.27 to -1.46). Surgeons should advise patients specifically about these increased risks when obtaining informed consent and be meticulous about their peri-operative care. Cite this article: Bone Joint J 2014;96-B:1637–43

Aims. This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates. Methods. A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed. Results. There were 4,135 TKAs (2,068 resurfaced and 2,027 unresurfaced) identified in 35 separate cohorts from 33 peer-reviewed studies. Anterior knee pain rates were significantly higher in unresurfaced knees overall (odds ratio (OR) 1.84; 95% confidence interval (CI) 1.20 to 2.83; p = 0.006) but more specifically associated with CR implants (OR 1.95; 95% CI 1.0 to 3.52; p = 0.030). There was a significantly better Knee Society function score (mean difference (MD) -1.98; 95% CI -1.1 to -2.84; p < 0.001) and Oxford Knee Score (MD -2.24; 95% CI -0.07 to -4.41; p = 0.040) for PS implants when patellar resurfacing was performed, but these differences did not exceed the minimal clinically important difference for these scores. There were no significant differences in complication rates or infection rates according to implant design. There was an overall significantly higher reoperation rate for unresurfaced TKA (OR 1.46 (95% CI 1.04 to 2.06); p = 0.030) but there was no difference between PS or CR TKA. Conclusion. Patellar resurfacing, when performed with CR implants, resulted in lower rates of anterior knee pain and, when used with a PS implant, yielded better knee-specific functional outcomes. Patellar resurfacing was associated with a lower risk of reoperation overall, but implant type did not influence this. Cite this article: Bone Joint J 2023;105-B(6):622–634

Aims. Different methods of anterior cruciate ligament (ACL) reconstruction have been described for skeletally immature patients before closure of the growth plates. However, the outcome and complications following this treatment remain unclear. The aim of this systematic review was to analyse the outcome and complications of different techniques which may be used for reconstruction of the ACL in these patients. Materials and Methods. We performed a systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. This involved a comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using the following combinations of keywords, “knee”, “anterior cruciate ligament”, “reconstruction”, “injury”, “children”, “adolescent”, “skeletally immature”, “open physis” and “surgery”. Results. A total of 53 studies met the inclusion criteria and were included for analysis. The overall rate of disturbance of growth after ACL reconstruction was 2.6%, with no statistical difference between transphyseal and physeal-sparing techniques. Physeal-sparing techniques had a lower rate of post-operative complications compared with transphyseal techniques (p = 0.0045). Outcomes assessed were Lysholm score, International Knee Documentation Committee (IKDC) score, the IKDC grade, the Tegner score and the KT-1000. Both techniques had similar clinical outcomes. Conclusions. This review reveals low rates of disturbance of growth after ACL reconstruction in skeletally immature patients. Although limited, the available evidence did not support any particular surgical technique when considering disturbance of growth or clinical outcome. Further randomised controlled trials are needed to investigate the efficacy of differing surgical techniques on outcomes in skeletally immature patients. Cite this article: Bone Joint J 2017;99-B:1053–60

Aims. Patients with osteoarthritis of the knee commonly have degenerative meniscal tears. Arthroscopic meniscectomy is frequently performed, although the benefits are debatable. Recent studies have concluded that there is no role for arthroscopic washout in osteoarthritis of the knee. Our aim was to perform a systematic review to assess the evidence for the efficacy of arthroscopic meniscectomy in patients with meniscal tears and degenerative changes in the knee. Patients and Methods. A literature search was performed, using the PubMed/MEDLINE database, for relevant articles published between 1975 and 2015. A total of six studies, including five randomised controlled trials and one cross-sectional study of a prospective cohort, met the inclusion criteria. Relevant information including study design, operations, the characteristics of the patients, outcomes, adverse events and further operations were extracted. Results. The degree of osteoarthritis in the patients who were included and the rate of cross over from one form of treatment to another varied in the studies. Two randomised controlled trials showed a benefit of arthroscopic surgery in patients with limited degenerative joint disease, compared with conservative treatment. One cross-sectional study showed that patients with less severe degenerative changes had better outcomes. Conclusion. Patients with symptomatic meniscal tears and degenerative changes in the knee can benefit from arthroscopic meniscectomy, particularly if the osteoarthritis is mild. A trial of conservative management may be effective and should be considered, especially in patients with moderate osteoarthritis. Cite this article: Bone Joint J 2016;98-B:934–8

Objectives. A lack of connection between surgeons and patients in evaluating the outcome of total knee arthroplasty (TKA) has led to the search for the ideal patient-reported outcome measure (PROM) to evaluate these procedures. We hypothesised that the desired psychometric properties of the ideal outcome tool have not been uniformly addressed in studies describing TKA PROMS. Methods. A systematic review was conducted investigating one or more facets of patient-reported scores for measuring primary TKA outcome. Studies were analysed by study design, subject demographics, surgical technique, and follow-up adequacy, with the ‘gold standard’ of psychometric properties being systematic development, validity, reliability, and responsiveness. Results. A total of 38 articles reported outcomes from 47 different PROMS to 85 541 subjects at 26.3 months (standard deviation 30.8) post-operatively. Of the 38, eight developed new scores, 20 evaluated existing scores, and ten were cross-cultural adaptation of existing scores. Only six of 38 surveyed studies acknowledged all ‘gold standard’ psychometric properties. The most commonly studied PROMS were the Oxford Knee Score, New Knee Society Score, Osteoarthritis Outcome Score, and Western Ontario and McMaster Universities Osteoarthritis Index. Conclusions. A single, validated, reliable, and responsive PROM addressing TKA patients’ priorities has not yet been identified. Moreover, a clear definition of a successful procedure remains elusive. Cite this article: Bone Joint Res 2015;4:120–127

Aims

The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Aims

Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening.

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The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

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The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources.

Aims

With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting.

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The optimal bearing surface design for medial unicompartmental knee arthroplasty (UKA) remains controversial. The aim of this study was to compare outcomes of fixed-bearing (FB) and mobile-bearing (MB) UKAs from a single high-volume institution.

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Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs.

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The aim of this study was to determine whether obesity had a detrimental effect on the long-term performance and survival of medial unicompartmental knee arthroplasties (UKAs).

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The aim of this study was to describe and compare joint-specific and generic health-related quality of life outcomes of the first versus second knee in patients undergoing staged bilateral total knee arthroplasty (BTKA) for osteoarthritis.

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The tibial component of total knee arthroplasty can either be an all-polyethylene (AP) implant or a metal-backed (MB) implant. This study aims to compare the five-year functional outcomes of AP tibial components to MB components in patients aged over 70 years. Secondary aims are to compare quality of life, implant survivorship, and cost-effectiveness.