Oxford Phase 3 unicompartmental knee arthroplasty: medium-term results of a minimally invasive surgical procedure

PURPOSE: In the last decade, a major increase in the use of and interest in unicompartmental knee arthroplasty (UKA) has developed. The Oxford Phase 3 UKA is implanted with a minimally invasive technique using newly developed instruments. The objective of this prospective study was to evaluate the outcome of UKA in patients with medial osteoarthritis of the knee in a high-volume unit. METHODS: Two-hundred and forty-four UKAs were performed with a minimally invasive approach. The median age was 72 (43-91) years. The median follow-up was 4.2 years (range 1-10.4 years). Fourteen patients died, and nine were considered to be lost to follow-up, but all had a well-functioning prosthesis in situ until their last follow-up. Pain, function and health-related quality of life were evaluated pre- and postoperatively using patient- and assessor-based outcome scores, as well as radiographic evidence. RESULTS: The mean Knee Society knee and function scores, WOMAC-scores, Oxford-score and VAS pain and satisfaction all improved. Nine knees required revision. Eleven patients required an additional arthroscopic procedure due to persisting pain secondary to intra-articular pathology, and four patients required manipulation under anaesthesia because of limited range of motion. The 7-year cumulative survival rate of the arthroplasty was 94.4%. A low incidence (21%) of a radiolucent line beneath the tibial component was observed at 5 years of follow-up. CONCLUSION: This study showed a high survival rate of the Oxford Phase 3 UKA. Patient satisfaction and functional performance were also very high. Major complication rate was low; in addition, the incidence of radiolucency under the tibial component, when compared to present literature, was low. When strict indication criteria are followed, excellent, durable, and in our opinion reliable, results can be expected for this procedur

Generalization of fear of movement-related pain and avoidance behavior as predictors of work resumption after back surgery:a study protocol for a prospective study (WABS)

BACKGROUND: Previous studies indicated that about 20% of the individuals undergoing back surgery are unable to return to work 3 months to 1 year after surgery. The specific factors that predict individual trajectories in postoperative pain, recovery, and work resumption are largely unknown. The aim of this study is to identify modifiable predictors of work resumption after back surgery. METHODS: In this multisite, prospective, longitudinal study, 300 individuals with radicular pain undergoing a lumbar decompression will be followed until 1-year post-surgery. Prior to surgery, participants will perform a computer task to assess fear of movement-related pain, avoidance behavior, and their generalization to novel situations. Before and immediately after surgery, participants will additionally complete questionnaires to assess fear of movement-related pain, avoidance behavior, optimism, expectancies towards recovery and work resumption, and the duration and severity of the pain. Six weeks, 3 months, 6 months, and 12 months after surgery, they will again complete questionnaires to assess sustainable work resumption, pain severity, disability, and quality of life. The primary hypothesis is that (generalization of) fear of movement-related pain and avoidance behavior will negatively affect sustainable work resumption after back surgery. Second, we hypothesize that (generalization of) fear of movement-related pain and avoidance behavior, negative expectancies towards recovery and work resumption, longer pain duration, and more severe pain before the surgery will negatively affect work resumption, pain severity, disability, and quality of life after back surgery. In contrast, optimism and positive expectancies towards recovery and work resumption are expected to predict more favorable work resumption, better quality of life, and lower levels of pain severity and disability after back surgery. DISCUSSION: With the results of this research, we hope to contribute to the development of strategies for early identification of risk factors and appropriate guidance and interventions before and after back surgery. Trial registration The study was preregistered on ClinicalTrials.gov: NCT04747860 on February 9, 2021. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40359-022-00736-5

Predictors of outcome of non-displaced fractures of the base of the fifth metatarsal

The purpose of this study was to identify those factors that influence the outcome after conservative treatment of undisplaced fractures of the fifth metatarsal. This was done with univariate analyses and, for the first time, with regression analyses of day-to-day clinical practice. Thirty-eight patients were treated with plaster and periods of no weight bearing (NWB). Their mean age was 48 years. They were evaluated using the Olerud ankle score, with analogue scales for pain and comfort, and with questions about cosmesis and wearing of shoes. Six patients sustained a Jones fracture and 32 a tuberosity avulsion fracture. The mean period of NWB was 17 days and of casting was 38 days. Three Jones fractures and all the avulsion fractures were healed at the end of treatment. After a mean of 490 days, the global ankle score was 82/100. Ten patients reported problems with shoes and nine reported cosmetic problems. The linear analogue scale for pain was 2.11/10 and for comfort 8.42/10. Gender, age, and fracture type did not affect outcome. The most significant predictor of poor functional outcome was longer NWB, which was strongly associated with worse global outcome, discomfort, and reported stiffness. NWB should be kept to a minimum for acute avulsions of the tuberosity of the fifth metatarsal

Correlation of positioning and clinical results in Oxford UKA

In a prospective clinical study, 59 patients with anteromedial osteoarthritis of the knee (61 knee joints) underwent minimally invasive medial Oxford unicompartmental arthroplasty phase 3. Clinical and radiographic examinations of 56 knees were carried out at five (4–7) years. American Knee Society (AKS) scores improved from mean 45.5 (20–80) points (knee score) and 55 (15–100) points (function score) before surgery to 90 (30–100) points in both scores after surgery. The position of each implant was determined on screened radiographs using an image intensifier. The implant position was analysed according to the Oxford X-ray rating system. We evaluated nine measures, and there was no detectable correlation between implant position and clinical result. However, long-term studies are needed before it is possible to elaborate an evidence-based guideline on positioning