Background and aims. Hallux rigidus in the metatarsophalangeal joint (MTPJ) can be treated with arthroplasty to reduce pain and enhance motion. Few studies have investigated the functionality and the survival of HemiCap arthroplasty. Primarily we aimed to examine the medium to long-term functionality and the degree of pain after surgery. Secondarily the failure and revision rate of HemiCap implants. Methods. A total of 106 patients were operated with HemiCap arthroplasty (n=114) from 2006 to 2014, median age 53 (16 to 80) years, 78 females, 37 dorsal flange (DF) implants. Patient charts were reviewed retrospectively to collect revision data. Pre operative Coughlin/Shurnas arthrosis degree, hallux valgus (HV), intermetatarsalintermetatarsal (IM) and Distal Metaphyseal Articular Angle (DMAA) angles was were measured. Pre- and post operative 3 weeks, 6 months, 1 and 2 year2-year pain levels of the first MTPJ by Visuel Analog Skala (VAS 1–10), American Orthopaedic Foot and Ankle Score (AOFAS 0 to 100 points) and, Range of Motion (ROM), were available for 51 patients. FortysevenForty-seven of the 70 available for reexamination partook in a cross sectional follow up where the Self-Reported Foot and Ankle Score (SEFAS 0–48 points) was added to the Patients Related Outcome Measures (PROMs). Statistics. Kaplan-Meier for survival analysis, adjusted for sex, radiological angles, degree of arthrosis and dorsal flange. Prospective PROMs and ROM compared by paired t-test. Results. At 3, 5 and 7 years we had an mean implant survival of 85%, 83% and 78%. Almost all were revised due to pain, one due to malalignment and one due to loosening of the Hemicap. Dorsal flange, gender, preoperative arthrosis degree, HV, IM or DMAA angles did not statistically influence the result. For those (n=23) that were re-examined, preoperative dorsal ROM changed from mean(sd) 21 (6) to 42 (18) degrees, VAS from 7 (2) to 2 (2) and AOFAS from 61 (11) to 87 (11) (p < 0.001). At mean 5 year follow up (n=47), mean (sd) dorsal ROM was 46 (17) degrees,. AOFAS was 84 (9), VAS 2 (1) and SEFAS 42 (6) points. The dorsal flange made no statistical significant difference for ROM or PROMs, but DF displayed 51 degrees of extension vs. 44 without (p=0.1). Periprostethic lucency (<2 mm) was observed in 27/47. Conclusions. In general, we saw an acceptable implant survival rate. We did not find any predictors that influenced implant failure and the design alterations with the dorsal flange are not evident clinically. Patients who were not revised had significantly less pain, greater ROM, and better overall foot and ankle conditions than preoperatively, but the data are biased by missing numbers and revisions

Background. Severe hallux rigidus can be treated with total or hemi arthroplasty to preserve motion in the 1st metatarsophalangeal joint (MTPJ). Decreased dorsiflexion impairs the rollover motion of the 1st MTPJ and recent studies of patients with 1st MTPJ osteoarthritis show increased plantar forces on the hallux. Objectives. Our aim was to examine the plantar force variables under the hallux and the 1st, 2nd, and 3rd – 5th distal metatarsal head (MH) on patients operated with a proximal hemiarthroplasty (HemiCap) in the 1st MTPJ and compare to a control group of healthy patients. Secondary aims: To examine correlations between the force and the 1st MTPJ range of motion (ROM) and pain. Study Design & Methods. Seventy patients operated with HemiCap were invited. 41 were included, (10 men, 31 women), median operation date 2011(range 2007–2014), age 63(47–78), 37 unilateral and 4 bilateral. Dorsal ROM of the 1st MTPJ was measured by goniometer and by x-ray. Pain evaluated by visual analog scale (VAS 1–10) during daily activities (DA) and during testing (DT). Emed (Novel) Foot Pressure Mapping system was used to measure peak force (N) and force/time integral (N/s) under the hallux, 1st and 2nd and 3–5th metatarsal heads (MH). Statistics: Force variables between operated feet and control group were compared by independent two-sample t-test or Wilcoxon rank sum test. Force variables association to ROM and pain by linear regression models. Results. Median (range) for HemiCap/Control group: Peak force (N): Hallux: 12(1–26)/20(4–30), 1st MH: 17(8–41)/24(14–42), 2nd MH 24(15–37)/28(24–37), 3rd–5th MH: 27(18–36)/30(25–35). Force/time integral (N/s): Hallux: 1(1–4)/4(1–12), 1st MH: 5(2–18)/7(3–11), 2nd MH 8(4–13)/10(7–13), 3rd–5th MH: 9(6–15)/10(8–14). Significant difference between HemiCap patients and healthy controls in peak force and force/time integral was found under the hallux (p<0.01), 1st (p<0.05) and 2nd MH (p<0.05), and max force under the 3–5th MH (p<0.01). Dorsal ROM of the operated feet was 45 degrees (10–75) by goniometer and 41 degrees (16–70) by x-ray. An increase in dorsal ROM decreased the peak force and force/time integral under the hallux (p>0.05) but not under the MHs. Most patients reported no pain (VAS 1: 62% DA, 78% DT), only 2 patients reported VAS>3. No significant correlation between pain and force or force/time integral. Conclusions. A mid-term hemiarthroplasty do not restore the joint motion to normal. The loading patterns are in opposition to AO patients as as assfgjkdfgjkfdgjk the HemiCap patients show a significantly decreased peak force and force/time integral under the hallux compared to the control group and the larger the dorsiflexion achieved postoperatively the smaller the force/time integral becomes. It may reflect a patient reluctance to load the 1st ray and 2nd MH. The plantar forces are not linked to pain. Most report minimal pain, but the pain score is biased by missing numbers and exclusion of revisions

Background. Focal resurfacing can treat localised articular damage of the knee not appropriate for arthroplasty or biological repair. Independent results on these implants are limited. We previously published early results showing significantly improved Knee Injury & Osteoarthritis Outcome Score (KOOS4) without complication or re-operation, demonstrating this system gives good analgesia and functional improvement in selected patients. We present long-term follow-up of these patients. Methods. We prospectively evaluated medium- to long-term results in patients with localised, full-thickness articular cartilage defects of the knee undergoing HemiCAP resurfacing. All procedures were performed by one consultant surgeon. Post-operative rehabilitation was standardised. Outcome measures were KOOS4 score, visual analogue score (VAS), Kellgren and Lawrence arthritis grade, and re-operation rates. Results. Six patients were evaluated with mean follow-up time of 74 months (range 61–96). Mean age was 44.8 years (range 33–51). One lateral and five medial compartments were resurfaced. Mean pre-operative KOOS4 was 39.1, mean 22-month follow-up KOOS4 improved significantly to 79.6, and mean latest follow-up KOOS4 remained good at 71.3. Mean VAS was 8.8 at latest follow-up. There was no loosening, migration or increase in osteoarthritis grade. One patient underwent revision to unicondylar knee replacement for pain after three years with comparable results at another centre (medial compartment, two year follow-up pre-revision KOOS4 84.6, latest follow-up post-revision KOOS4 73.6, VAS 6). Cause of pain was unclear (heel pain causing prolonged altered weight-bearing or failure of HemiCAP). Conclusion. Our results demonstrate that the use of the joint-preserving HemiCAP system provides good pain relief and functional improvement in both the short and longer-term. Few studies assess functional outcomes of focal resurfacing for localised full thickness articular cartilage defects. Our study assesses both the contemporaneous and time-dependent behaviour of focal resurfacing. We believe this is one of the longest follow-up series to date