Aims. The aim of the present study was to assess the outcomes of the induced membrane technique (IMT) for the management of infected segmental bone defects, and to analyze predictive factors associated with unfavourable outcomes. Methods. Between May 2012 and December 2020, 203 patients with infected segmental bone defects treated with the IMT were enrolled. The digital medical records of these patients were retrospectively analyzed. Factors associated with unfavourable outcomes were identified through logistic regression analysis. Results. Among the 203 enrolled patients, infection recurred in 27 patients (13.3%) after bone grafting. The union rate was 75.9% (154 patients) after second-stage surgery without additional procedures, and final union was achieved in 173 patients (85.2%) after second-stage surgery with or without additional procedures. The mean healing time was 9.3 months (3 to 37). Multivariate logistic regression analysis of 203 patients showed that the number (≥ two) of debridements (first stage) was an independent risk factor for infection recurrence and nonunion. Larger defect sizes were associated with higher odds of nonunion. After excluding 27 patients with infection recurrence, multivariate analysis of the remaining 176 patients suggested that intramedullary nail plus plate internal fixation, smoking, and an allograft-to-autograft ratio exceeding 1:3 adversely affected healing time. Conclusion. The IMT is an effective method to achieve infection eradication and union in the management of infected segmental bone defects. Our study identified several risk factors associated with unfavourable outcomes. Some of these factors are modifiable, and the risk of adverse outcomes can be reduced by adopting targeted interventions or strategies. Surgeons can fully inform patients with non-modifiable risk factors preoperatively, and may even use other methods for bone defect reconstruction. Cite this article: Bone Joint J 2024;106-B(6):613–622

Aims. The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT. Methods. A systematic search was performed in CINAHL, The Cochrane Library, Embase, Ovid MEDLINE, and PubMed. We included articles from 1 January 1980 to 30 September 2019. Studies with a minimum sample size of five cases, where the IMT was performed primarily in adult patients (≥ 18 years old), in a long bone were included. Multivariate regression models were performed on patient-level data to determine variables associated with nonunion, postoperative infection, and the need for additional procedures. Results. A total of 48 studies were included, with 1,386 cases treated with the IMT. Patients had a mean age of 40.7 years (4 to 88), and the mean defect size was 5.9 cm (0.5 to 26). In total, 82.3% of cases achieved union after the index second stage procedure. The mean time to union was 6.6 months (1.4 to 58.7) after the second stage. Our multivariate analysis of 450 individual patients showed that the odds of developing a nonunion were significantly increased in those with preoperative infection. Patients with tibial defects, and those with larger defects, were at significantly higher odds of developing a postoperative infection. Our analysis also demonstrated a trend towards the inclusion of antibiotics in the cement spacer having a protective effect against the need for additional procedures. Conclusion. The IMT is an effective management strategy for complex segmental bone defects. Standardized reporting of individual patient data or larger prospective trials is required to determine the optimal implementation of this technique. This is the most comprehensive review of the IMT, and the first to compile individual patient data and use regression models to determine predictors of outcomes. Cite this article: Bone Joint J 2020;102-B(12):1723–1734

Aims. Treatment of chronic osteomyelitis (COM) for young patients remains a challenge. Large bone deficiencies secondary to COM can be treated using induced membrane technique (IMT). However, it is unclear which type of bone graft is optimal. The goal of the study was to determine the clinical effectiveness of bone marrow concentrator modified allograft (BMCA) versus bone marrow aspirate mixed allograft (BMAA) for children with COM of long bones. Methods. Between January 2013 and December 2017, 26 young patients with COM were enrolled. Different bone grafts were applied to repair bone defects secondary to IMT procedure for infection eradication. Group BMCA was administered BMCA while Group BMAA was given BMAA. The results of this case-control study were retrospectively analyzed. Results. Patient infection in both groups was eradicated after IMT surgery. As for reconstruction surgery, no substantial changes in the operative period (p = 0.852), intraoperative blood loss (p = 0.573), or length of hospital stay (p = 0.362) were found between the two groups. All patients were monitored for 12 to 60 months. The median time to bone healing was 4.0 months (interquartile range (IQR) 3.0 to 5.0; range 3 to 7) and 5.0 months (IQR 4.0 to 7.0; range 3 to 10) in Groups BMCA and BMAA, respectively. The time to heal in Group BMCA versus Group BMAA was substantially lower (p = 0.024). Conclusion. IMT with BMCA or BMAA may attain healing in large bone defects secondary to COM in children. The bone healing time was significantly shorter for BMCA, indicating that this could be considered as a new strategy for bone defect after COM treatment. Cite this article: Bone Joint Res 2021;10(1):31–40

Aims. To clarify the effectiveness of the induced membrane technique (IMT) using beta-tricalcium phosphate (β-TCP) for reconstruction of segmental bone defects by evaluating clinical and radiological outcomes, and the effect of defect size and operated site on surgical outcomes. Methods. A review of the medical records was conducted of consecutive 35 lower limbs (30 males and five females; median age 46 years (interquartile range (IQR) 40 to 61)) treated with IMT using β-TCP between 2014 and 2018. Lower Extremity Functional Score (LEFS) was examined preoperatively and at final follow-up to clarify patient-centered outcomes. Bone healing was assessed radiologically, and time from the second stage to bone healing was also evaluated. Patients were divided into ≥ 50 mm and < 50 mm defect groups and into femoral reconstruction, tibial reconstruction, and ankle arthrodesis groups. Results. There were ten and 25 defects in the femur and tibia, respectively. Median LEFS improved significantly from 8 (IQR 1.5 to 19.3) preoperatively to 63.5 (IQR 57 to 73.3) at final follow-up (p < 0.001). Bone healing was achieved in all limbs, and median time from the second stage to bone healing was six months (IQR 5 to 10). Median time to bone healing, preoperative LEFS, or postoperative LEFS did not differ significantly between the defect size groups or among the treatment groups. Conclusion. IMT using β-TCP provided satisfactory clinical and radiological outcomes for segmental bone defects in the lower limbs; surgical outcomes were not influenced by bone defect size or operated part. Cite this article: Bone Joint J 2021;103-B(3):456–461

Aim. The induced membrane technique (IMT) or Masquelet technique is a two-step surgical procedure used to treat bony defects (traumatic or resulting from tumoral resections) and pseudo arthroses, even caused by infections. The relatively small case series reported, sometimes with variants to the original technique, make it difficult to assess the real value of the technique. Aim of this study was then to undertake a systematic review of the literature with a particular focus on bone union, infection eradication and complication rates. Method. A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Individual Patient Data (PRISMA-IPD) guidelines. PubMed and other medical databases were searched using “Masquelet technique” and “induced membrane technique” keywords. English, French or Italian written articles were included if dealing with IMT employed to long bones in adults and reporting at least 5 cases with a 12 months minimum follow-up. Clinical and bone defect features, aetiology, surgical data, complications, re-interventions, union and infection eradication rates were recorded into a database. Fischer's exact test and unpaired t-test were used for the statistical analysis on the individual patient's data. Results. Ten papers met the inclusion criteria (312 patients), but only 5 reported individual patients data (65 cases). IMT was used for acute bone loss (53%), septic (47%) and aseptic (7%) pseudo arthroses and tumour resections (2%). Bone defect length ranged from 0.6 to 26 cm. Overall, union rate was achieved in 88% of the cases and infection cured in 93%. Complication rate was 53%. Surgical variants included the use of antibiotic-loaded spacers (59.9%), internal fixation during the first step (62.1%), use of Reamer-Irrigator-Aspirator technique (40.1%) instead of iliac crest (63.1%) grafting, bone substitutes (18.3%) and growth factors addition (41%). No statistical differences were found comparing patient-related factors or surgical variants in achieving the two outcomes. Conclusions. IMT is effective to achieve bone union and infection eradication, but is associated with a high rate of complications and re-interventions. This should be taken into consideration by the surgeons and be a part of the informed consent. This systematic review was limited by the few studies meeting the inclusion criteria and their high variability in data reporting, making a meta-analysis impossible to undertake. Further studies are needed to demonstrate the role the patients’ clinical features and IMT variants with respect to bone union and infection eradication

In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare bone healing in rabbits with a chronically infected non-union compared to non-infected equivalents. A 5 mm defect was created in the humerus and filled with a polymethylmethacrylate (PMMA) spacer or left empty (n=6 per group). After 3 weeks, the PMMA spacer was replaced with a beta-tricalcium phosphate (chronOs, Synthes) scaffold, which was placed within the induced membrane and observed for a further 10 weeks. The same protocol was followed for the infected group, except that four week prior to treatment, the wound was inoculated with Staphylococcus aureus (4×10. 6. CFU/animal) and the PMMA spacer was loaded with gentamicin, and systemic therapy was applied for 4 weeks prior to chronOs application. All the animals from the infected group were culture positive during the first revision surgery (mean 3×10. 5. CFU/animal, n= 12), while at the second revision, after antibiotic therapy, all the animals were culture negative. The differences in bone healing between the non-infected and infected groups were evaluated by radiography and histology. The initially infected animals showed impaired bone healing at euthanasia, and some remnants of bacteria in histology. The non-infected animals reached bone bridging in both empty and chronOs conditions. We developed a preclinical in vivo model to investigate how bacterial infection influence bone healing in large defects with the future aim to explore new treatment concepts of infected non-union

Background: First Metatarsophalangeal joint (MTP) arthrodesis is commonly performed for hallux valgus with an arthritic joint, however previous studies have recommended that this should be combined with another procedure to correct the hallux valgus when the intermetatarsal angle is enlarged. We propose that an arthrodesis of the first MTP joint with a soft tissue release produces a significant correction of the intermetatarsal angle in such a group of patients avoiding the need for a concomitant procedure to change the intermetatatarsal angle. Patients and Methods: The charts and radiographs of 20 patients who had an arthrodesis of the first MTP joint were retrospectively reviewed. All 20 patients were female with a mean age of 54.2 years (range 42–78 years). The intermetatarsal (IMT) angles were measured by two individuals independently. These were measured on a weight-bearing pre-operative film and a weight-bearing 6-week post-operative film. Fusions were performed using either the Hallu-S® plate or two crossed screws. A Student “t” test was performed on the change of the IMT angle and also on the inter-observer variations for the same. Results: The mean pre-operative IMT angle was 16.85° (range 12–30°). The mean post-operative IMT angle was 10.6° (range 6–20°). The mean change in the IMT angle was 6.25° (range 2–12°). This change of the IMT angle was statistically significant – p< 0.0001 – Student “t” test. There was no significance in the inter-observer difference (p> 0.5) note in 6 radiographs with a mean of 1.3° (range 1–2°). Conclusion: This is the first study to show that performing an arthrodesis of the first MTP joint with soft tissue release in patients with hallux valgus and degenerate first MTP joint will significantly correct the IM angle. Therefore, this alleviates the need for performing another procedure on these patients

The Masquelet or induced membrane technique (IMT) is a two-stage surgical procedure used for the treatment of segmental bone defects. In this technique, the defect is first filled with a polymethyl methacrylate (PMMA) spacer, which triggers the formation of a membrane that will encapsulate the defect. During the second surgery, the spacer is carefully removed and replaced by autologous bone graft while preserving the membrane. This membrane is vascularized, contains growth factors, and provides mechanical stability to the graft, all of which are assumed to prevent graft resorption and promote bone healing. The technique is gaining in popularity and several variations have been introduced in the clinical practice. For instance, orthopaedic surgeons now often include antibiotics in the spacer to treat or prevent infection. However, the consequences of this approach on the properties of the induce membrane are not fully understood. Accordingly, in a small animal model, this study aimed to determine the impact on the induced membrane of impregnating spacers with antibiotics frequently used in the IMT. We surgically created a five-mm segmental defect in the right femur of 25 adult male Sprague Dawley rats. The bone was stabilized with a plate and screws before filling the defect with a PMMA spacer. Animals were divided into five equal groups according to the type and dose of antibiotics impregnated in the spacer: A) no antibiotic (control), B) low-dose tobramycin (1.2 g/40 g of PMMA), C) low-dose vancomycin (1 g/40 g of PMMA), D) high-dose tobramycin (3.6 g/40 g of PMMA), E) high-dose vancomycin (3 g/40 g of PMMA). The animals were euthanized three weeks after surgery and the induced membranes were collected and divided for analysis. We assessed the expression of selected genes (Alpl, Ctgf, Runx2, Tgfb1, Vegfa) within the membrane by quantitative real-time PCR. Moreover, frozen sections of the specimens were used to quantify vascularity by immunohistochemistry (CD31 antigen), proliferative cells by immunofluorescence (Ki-67 antigen), and membrane thickness. Microscopic images of the entire tissue sections were taken and analyzed using FIJI software. Finally, we measured the concentration of vascular endothelial growth factor (VEGF) in the membranes by ELISA. No significant difference was found among the groups regarding the expression of genes related to osteogenesis (Alpl, Runx2), angiogenesis (Vegfa), or synthesis of extracellular matrix (Ctgf, Tgfb1) (n = four or five). Similarly, the density of proliferative cells and blood vessels within the membrane, as well as the membrane thickness, did not vary substantially between the control, low-dose, or high-dose antibiotic groups (n = four or five). The concentration of VEGF was also not significantly influenced by the treatment received (n = four or five). The addition of tobramycin or vancomycin to the spacer, at the defined low and high doses, does not significantly alter the bioactive characteristics of the membrane. These results suggest that orthopaedic surgeons could use antibiotic-impregnated spacers for the IMT without compromising the induced membrane and potentially bone healing

Aims: Both clinical and epidemiologic studies have shown an association between atherosclerotic changes in the aorta or lumbar arteries and lumbar disc degeneration. However, the association between atherosclerosis and sciatica is unknown. The aim of this study was to investigate the association between carotid intima-media thickness (IMT) and clinically defined sciatica in a representative population sample. Methods: The target population consisted of people aged 45–74 years who had participated in a nationwide Finnish population study during 2000–2001 and lived within 200 kilometres from the six study clinics. Of the 1867 eligible subjects, 1386 (74%) were included in the study. High-resolution B-mode ultrasound imaging was used to measure IMT. Local or radiating low back pain (LBP) was determined by a standard interview and clinical signs of sciatica by physician’s clinical examination. Results: Carotid IMT was associated with continuous radiating LBP and with a positive unilateral clinical sign of sciatica. The associations were seen only in men; after adjustment for potential confounders, each standard deviation (0.23 mm) increment in carotid IMT showed an odds ratio of 1.6 (95% confidence interval 1.1–2.3) for continuous radiating LBP and 1.7 (95% confidence interval 1.3–2.1) for a positive unilateral clinical sign of sciatica. This latter association was observed in subjects with and in those without exposure to physical work load factors. Carotid IMT was not associated with local LBP. Conclusions: Sciatica may be a manifestation of atherosclerosis, or both conditions may share common risk factors

Introduction and Aims: We investigated the hypothesis that the effects of muscle-tendon surgery could be controlled or ‘dosed’ by varying the location of intramuscular tenotomy (IMT) or fascial striping within the muscle-tendon unit (MTU). We performed a series of randomised trials in paired cadaver MTUs of tibialis posterior, semitendinosus, gracilis and semimembranosus. Method: Following dissection of 10 paired cadaver MTUs of the above-mentioned muscles, we performed a series of randomised trials in which each pair of MTUs received a low or high IMT. ‘Low IMT’ was defined as an IMT performed two centimetres proximal to the distal musculotendinous junction. ‘High IMT’ was performed two centimetres distal to the start of the first tendinous fibres in the proximal muscle belly. The force-length characteristics were then determined by tensile load testing until failure on an Instron machine. The load and lengthening at failure for each pair of MTUs were compared by paired t test. Results: As expected, there were significant differences in the load versus length curves for different muscles and for different simulated surgeries (IMT versus fascial striping). The mean load at failure was significantly lower for all low IMTs compared to high IMTs in all MTUs tested e.g. tibialis posterior: mean difference low versus high = 13N (95% CI 6.8, 19.2 p< 0.001). The lengthening at failure was also greater for low IMTs than for high IMTs. The difference reached statistical significance only in tibialis posterior. Conclusions: The site of the intramuscular surgery or fascial striping has a direct bearing on the force versus lengthening curve. We hypothesise that the same principle applies during muscle tendon surgery in children with spastic contractures and that it may be possible to graduate surgical lengthening, according to the correction required

A large number of total hip arthroplasties (THA) are performed each year, of which 60 % use cementless femoral fixation. This means that the implant is press-fitted in the bone by hammer blows. The initial fixation is one of the most important factors for a long lasting fixation [Gheduzzi 2007]. It is not easy to obtain the point of optimal initial fixation, because excessively press-fitting the implant by the hammer blows can cause peak stresses resulting in femoral fracture. In order to reduce these peak stresses during reaming, IMT Integral Medizintechnik (Luzern, Switzerland) designed the Woodpecker, a pneumatic reaming device using a vibrating tool. This study explores the feasibility of using this Woodpecker for implant insertion and detection of optimal fixation by analyzing the vibrational response of the implant and Woodpecker. The press-fit of the implant is quantified by measuring the strain in the cortical bone surrounding the implant. An in vitro study is presented. Two replica femur models (Sawbones Europe AB, Malmo Sweden) were used in this study. One of the femur models was instrumented with three rectangular strain gauge rosettes (Micro-Measurements, Raleigh, USA). The rosettes were placed medially, posteriorly and anteriorly on the proximal femur. Five paired implant insertions were performed on both bone models, alternating between standard hammer blow insertions and using the Woodpecker. The vibrational response was measured during the insertion process, at the implant and Woodpecker side using two shock accelerometers (PCB Piezotronics, Depew, NY, USA). The endpoint of insertion was defined as the point when the static strain stopped increasing. Significant trends were observed in the bandpower feature that was calculated from the vibrational spectrum at the implant side during the Woodpecker insertion. The bandpower is defined as the percentage power of the spectrum in the band 0–1000 Hz. Peak stress values calculated from the strain measurement during the insertion showed to be significantly (p < 0.05) lower at two locations using the Woodpecker compared to the hammer blows at the same level of static strain. However, the final static strain at the endpoint of insertion was approximately a factor two lower using the Woodpecker compared to the hammer. A decreasing trend was observed in the bandpower feature, followed by a stagnation. This point of stagnation was correlated with the stagnation of the periprosthetic stress in the bone measured by the strain gages. The behavior of this bandpower feature shows the possibility of using vibrational measurements during insertion to assess the endpoint of insertion. However it needs to be taken into account that it was not possible to reach the same level of static strain using the Woodpecker as with the hammer insertion. This could mean that either extra hammer blows or a more powerful pneumatic device could be needed for proper implant insertion

Introduction. Each year, a large number of total hip arthroplasties (THA) are performed, of which 60 % use cementless fixation. The initial fixation is one of the most important factors for a long lasting fixation [Gheduzzi 2007]. The point of optimal initial fixation, the endpoint of insertion, is not easy to achieve, as the margin between optimal fixation and a femoral fracture is small. Femoral fractures are caused by peak stresses induced during broaching or by the hammer blows when the implant is excessively press-fitted in the femur. In order to reduce the peak stresses during broaching, IMT Integral Medizintechnik (Luzern, Switzerland) designed the Woodpecker, a pneumatic broach that generates impulses at a frequency of 70 Hz. This study explores the feasibility of using the Woodpecker for implant insertion by measuring both the strain in the cortical bone and the vibrational response. An in vitro study is presented. Material and Methods. A Profemur Gladiator modular stem (MicroPort Orthopedics Inc. Arlington, TN, USA) and two artificial femora (composite bone 4th generation #3403, Sawbones Europe AB, Malmö, Sweden) were used. One artificial femur was instrumented with three rectangular strain gauge rosettes (Micro-Measurements, Raleigh, NC, USA). The rosettes were placed medially, posteriorly and anteriorly proximally on the cortical bone. Five paired implant insertions were repeated on both artificial bones, alternating between standard hammering and Woodpecker insertions. During the insertion processes the vibrational response was measured at the implant and Woodpecker side (fig. 1) using two shock accelerometers (PCB Piezotronics, Depew, NY, USA). Frequency spectra were derived from the vibrational responses. The endpoint of insertion was defined as the point when the static strain stopped increasing during the insertion. Results. Peak stress values calculated out of the strain measurement during the insertion showed to be significantly (p < 0.05) lower at two locations using the Woodpecker compared to the hammer blows at the same level of static strain. However, the final static strain at the endpoint of insertion was approximately a factor two lower using the Woodpecker compared to the hammer. During the last hammer insertion a fracture occurred, which was clearly visible in the frequency spectra. Figure 2 shows the sudden change between the spectra of the hit prior and after the fracture. Discussion/Conclusion. Peak stresses showed to be lower using the Woodpecker compared to hammer insertion, which is a promising result concerning fracture prevention. However it needs to be taken into account that it was not possible to reach the same level of static strain using the Woodpecker as with the hammer insertion. It is expected that the Woodpecker in its actual design is not able to reach a similar level of press-fit as hammer blows. Using vibrational data showed to be promising for fracture detection, as fractures are not always visible due to the soft tissue. For figures, please contact authors directly

The aim of the study was to assess the clinical, radiological and paedobarographic outcome following modified Silver’s McBride’s procedure, in the treatment of Hallux Valgus. Between 1997 and 1999, Modified Silver’s McBrides procedure for Hallux Valgus was performed on 38 foot in 28 patients (18 unilateral and 10 bilateral). The median age was 60 years. The median follow up was 26 weeks. Clinical outcome measures consisted of pain, deformity, mobility, walking ability and shoe wear. Radiological outcome measures were Hallux Valgus angle, Intermetatarsal angle, 1st to 5th Metatarsal distance, 1st to 2nd metatarsal distance, and the DMAA (Distal Metatarsal Articular Angle). Paedobarographic (Musgrave) outcome of peak pressure, total force, time from heel strike to toe lift off post operatively were analysed. Preoperative visual analogue pain score was 5–8 and 0–4 postoperatively (p< 0.001). 34 feet had pain on walking preoperatively and only 11 had pain post-operatively. 12 were wearing special shoes pre- operatively and 5 post-operatively. Hallux Valgus angle was 34 pre-operatively and 19 post-operatively (p< 0.001). IMT angle was 14.53 pre-op and 10.88 postop (p< 0.001). 1st-5th MT distance was 67mm pre- op and 63mm post-op (p=0.001). 1st-2nd MT distance was 15 pre-op and 10 post-op (p=0.004). DMAA was 24.7 degrees. 21 foot an obliquity of the 1st tarsometatarsal joint was seen indicating an anatomical cause of metatarsus varus. Foot pressure studies showed a peak pressure of 1.37kg/cm2 , heel to toe off- time was 936.9ms and maximum load was 65.2 kg. There were 3 cases of superficial wound problems. One patient developed Hallux varus deformity, with no functional disability. Conclusion: Modified Silver’s McBride procedure for the treatment of Hallux Valgus is a soft tissue procedure and is a safe alternative to the commonly practiced osteotomies for correction of this disorder

Aims

To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty.

Twenty-two patients who underwent thirty-four Kellers’ excision arthroplasty were followed up at an average of thirty-five months. They were assessed using AFAOS, satisfaction and radiological evaluation. The average hallux score was eighty- five (fifty-two to one hundred) while the average lesser toe score was ninety- two (seventy-five to one hundred). The average pain score was thirty- six (twenty to forty) for the hallux and thirty-eight for the lesser toes (twenty to forty). 23/34(68%) had good to excellent, 6/34 (18%) had fair and 5/34(14%) had poor results. The great toe was moderately short, but most patients do not seem to mind this. 91% patients were satisfied with the results. We undertook a retrospective study of Kellers’ excision arthroplasty done over the last seven years to assess the medium term results. Twenty-two patients who underwent thirty- four Kellers’ excision arthroplasty were followed up at an average of thirty-five months. They were followed up using the AFAOS, patient satisfaction and radiological evaluation. The average age at the time of surgery was 67.4 years. There were seventeen females (twenty-five feet) and five males (nine feet). All patients underwent bunionectomy along with excision of proximal third of the proximal phalanx. Of these twenty underwent K wire stablization of the hallux following excision. The average hallux score was eighty- five (range sixty-two to one hundred) while the average lesser toe score was ninety- two (range seventy-five to one hundred). The average pain score was thirty- six (range twenty to forty) for the hallux and thirty-eight for the lesser toes (twenty to forty). 23/34 (68%) had good to excellent, 6/34 (18%) had fair and 5/34(14%) had poor results. The average correction of the hallux valgus was 9o. The average IMT was 25o preoperatively and 18o postoperatively. The average shortening was 7 mm. Complications included two cases of transfer metatarsalgia and two cases of clawing of the lesser toes. One patient developed abscess which settled after incision and drainage. Thirty-one out of thirty-four patients were satis-fied with the final outcome and thirty out of thirty-four patients would have the operation on the other feet. The great toe is moderately short, but most patients do not seem to mind this. 91% patients were satisfied with the results

Early failure associated with adverse reactions to metal debris is an emerging problem after hip resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p < 0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear.

Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal hip resurfacing and replacement.