Aims. The Cartiva synthetic cartilage implant (SCI) entered mainstream use in the management of first metatarsophalangeal joint (MTPJ) arthritis following the positive results of large trials in 2016. Limited information is available on the longer-term outcomes of this implant within the literature, particularly when independent from the originator. This single-centre cohort study investigates the efficacy of the Cartiva SCI at up to five years. Methods. First MTPJ arthritis was radiologically graded according to the Hattrup and Johnson (HJ) classification. Preoperative and sequential postoperative patient-reported outcome measures (PROMs) were evaluated using the Manchester-Oxford Foot Questionnaire (MOXFQ), and the activities of daily living (ADL) sub-section of the Foot and Ankle Ability Measure (FAAM). Results. Patients were followed up for a mean of 66 months (SD 7.1). Of an initial 66 cases, 16 did not return PROM questionnaires. A total of six failures were noted, with survival of 82%. Overall, significant improvement in both objective scores (MOXFQ and FAAM ADL) was maintained versus preoperatively: 18.2 versus 58.0 (p > 0.001) and 86.2 versus 41.1 (p > 0.001), respectively. The improvement was noted to be less pronounced in males. Subjective scores had deteriorated since early follow-up, with an interval decrease in patient satisfaction from 89% to 68%. Furthermore, a subset of cases demonstrated clinically important interval deterioration in objective scores. However, no specific patient factors were found to be associated with outcomes following analysis. Conclusion. This study represents the longest-term independent follow-up in the literature. It shows reassuring mid-term efficacy of the Cartiva SCI with better-than-expected survival. However, deterioration in scores for a subset of patients and lower satisfaction may predict ongoing failure in this group of patients. Additionally, males were noted to have a lower degree of improvement in scores than females. As such, ongoing observation of the SCI to assess durability and survivability, and identify predictive factors, is key to improving patient selection. Cite this article: Bone Jt Open 2024;5(9):799–805

Introduction. Osteoarthritis commonly affects the first metatarsophalangeal joint. Stress across this joint has been postulated to increase the incidence of osteoarthritis. Certain foot structures have been associated with a higher incidence of osteoarthritis of the big toe. Utilizing finite elemental analysis, bone stress across the first metatarsophalangeal joint was calculated during mid stance phase of gait and compared in different foot structures. Method. A geometrically accurate three dimensional model of the first metatarsophalangeal joint was created utilising a high resolution 7 tesla MRI and Mimics v14 imaging software. Planus, rectus and cavus feet were simulated by varying the metatarsophalangeal declination angle to 10.1, 20.2 and 30.7 degrees, respectively. A non-manfold computer aided design technique in Mimics v14.2 and finite element method in ANSYS v12 FE were utilised to create the boundary conditions, representing the double support stance phase of gait. Using information from 61 asymptomatic patients with different foot types walking over a Novel emed-x plantar pressure measuring system, plantar loading conditions were applied. Finite elemental analysis was used to predict stress in the first metatarsophalangeal joint in the different foot types. Results. The peak stresses in the distal first metatarsophalangeal joint cartilage were 1.1×10(6) Pa, 6.0×10(5) Pa and 9.7×10(5) Pa for planus, rectus and cavus foot types, respectively. This corresponds to 83.3 percent and 61.6 percent increases in first metatarsophalangeal joint contact stress for the planus and cavus feet relative to the rectus foot. Conclusion. The results suggest there is a higher contact stress of the first metatarsophalangeal joint in patients with pes planus and pes cavus compared to the rectus foot. This may account for the increase risk of first metatarsophalangeal joint osteoarthritis in patients with pes planus. Further work has been initiated utilising this model to measure first metatarsophalangeal joint stress with different hindfoot loading

First metatarsophalangeal joint (MTPJ) arthrodesis plays a significant role in the management of symptomatic hallux rigidus. Several open and very few percutaneous techniques have been described in the literature. The authors present a new minimally invasive technique along with patient reported outcome, radiological parameters and a discussion on this novel technique. A total of fifteen cases of first MPTJ arthrodesis were included in this prospective continuous series from September 2011 to June 2012. Mean age was 56 years and the indication for surgery was hallux rigidus in 13 of 15 cases. All patients underwent the same minimally invasive procedure by the same primary surgeon (AHS), 13 of 15 as day cases. Clinical outcome and patient satisfaction were assessed by the Manchester-Oxford Foot Questionnaire (MOXFQ) preoperatively and at most recent follow up. Radiographic and clinical evaluation of fusion was also assessed. No patients were lost to follow up and all scores were collected by an independent surgical practitioner to avoid bias. Mean follow up was six months (range 1 to 9 months). The MOXFQ score for cases where fusion was achieved (n=14) improved from a mean 40/64 preoperatively to a mean 15/64 at last follow up (p=0.001). Patient satisfaction was overall very good. This minimally invasive technique for first MTPJ arthrodesis is simple and can achieve results similar or better than open techniques in experienced hands. Further cases are needed to expand this series and evaluate for further complications

Introduction:. This study evaluates the mid-term results of first metatarsophalangeal joint replacement (MTPJR) for hallux rigidus using the Toefit-Plus™ prosthesis. Methods:. We prospectively studied the outcomes of 86 MTPJR in 73 patients using the AOFAS-HMI score and radiological follow up over a period from 2006 to 2013, with surgeries performed by a single surgeon at two centres. Patients were reviewed, scored and radiographs obtained pre-operatively and then at intervals of 6 weeks, 6 months, 12 months and then yearly. The mean follow up was 33 months (2–72). Results:. The mean AOFAS score of the patients not requiring revision at 1 year was 92, at 2 years was 94, at 3 years was 91, at 4 years was 99, at 5 years was 93, at 6 years was 100 and at 7 years was 97. 18 joints have either been revised or listed for revision giving a revision rate of 21%; this occurred at a mean of 33 months post-surgery. Reasons for revision included loosening of components in 13, infection in 1, dislocation in 2, malalignment in 1 and persistent pain in 1. Eight patients sustained intra-operative fractures requiring circlage wiring, of which 7 went on to union and one required revision. 25 patients had evidence of radiological loosening of which 22 were around the phalangeal component and 3 were around the metatarsal component. Conclusions:. First MTPJ replacement resulted in improved outcomes in patients with hallux rigidus who do not require revision in the medium term, however the revision rate is unacceptably high and as such we have discontinued use of this prosthesis. Radiological loosening of the components is high and needs monitoring for progression which may necessitate revision

Aims

Arthroplasty for end-stage hallux rigidus (HR) is controversial. Arthrodesis remains the gold standard for surgical treatment, although is not without its complications, with rates of up to 10% for nonunion, 14% for reoperation and 10% for metatarsalgia. The aim of this study was to analyze the outcome of a double-stemmed silastic implant (Wright-Medical, Memphis, Tennessee, USA) for patients with end-stage HR.

Introduction/Purpose

A randomized clinical trial of first MTP joint hemiarthroplasty with a synthetic cartilage implant demonstrated equivalent pain, function and safety outcomes to first MTP joint arthrodesis at 2 years. Recognizing that many hemiarthroplasty and total toe implants have initially good results that deteriorate over time, the purpose of this study was to prospectively assess the safety and efficacy outcomes for the synthetic cartilage implant population and to determine if the excellent outcomes were maintained at >5 years.

Introduction. Studies have compared outcomes of first metatarsophalangeal joint (MTPJ1) implant hemiarthroplasty and arthrodesis, but there is a paucity of data on the influence of patient factors on outcomes. We evaluated data from a prospective, RCT of MTPJ1 implant hemiarthroplasty (Cartiva) and arthrodesis to determine the association between patient factors and clinical outcomes. Methods. Patients ≥18 years with Coughlin hallux rigidus grade 2, 3, or 4 were treated with implant MTPJ1 hemiarthroplasty or arthrodesis. Pain VAS, Foot and Ankle Ability Measure (FAAM) Sports and ADL, and SF-36 PF scores were obtained preoperatively, and at 2, 6, 12, 24, 52 and 104 weeks postoperatively. Final outcomes, MTPJ1 active peak dorsiflexion, secondary procedures, radiographs and safety parameters were evaluated for 129 implant hemiarthroplasties and 47 arthrodeses. Composite primary endpoint criteria for clinical success included pain reduction ≥30%, maintenance/improvement in function, and no radiographic complications or secondary surgical intervention at 24 months. Predictor variables included: grade; gender; age; BMI; symptom duration; prior MTPJ1 surgery; preoperative hallux valgus angle, ROM, and pain. Two-sided Fisher's Exact test was used (p< 0.05). Results. Patient demographics and baseline outcome measures were similar. Success rates between implant MTPJ1 hemiarthroplasty and arthrodesis were similar when stratified by hallux rigidus grade, gender, age, BMI, symptom duration, prior MTPJ1 surgery status, and preoperative VAS pain, hallux valgus and ROM (p0.05). Conclusion. Synthetic cartilage implant hemiarthroplasty (Cartiva) is an appropriate treatment for patients with hallux rigidus grade 2, 3 or 4 and is a reasonable choice in hallux rigidus in patients with < 20 degrees HVA, with a high degree of preoperative stiffness, irrespective of gender, age, BMI, hallux rigidus grade, preoperative pain, or duration of symptoms, in contrast to what might have been expected

Introduction

A randomized clinical trial of first metatarsophalangeal (MTP) joint hemiarthroplasty with a synthetic cartilage implant demonstrated equivalent pain, function and safety outcomes to first MTP joint arthrodesis at 2 years. The implant cohort continues to be followed under an extension of the original study and we report on prospectively determined 5+ year outcomes for subjects assessed to date.

Introduction:

Techniques devised for 1^st MTPJ arthrodesis have been described since 1979 when Humbert et al published a ‘tongue and trough’ technique. Common contemporary techniques include fixation with single or crossed screws, or dorsal plates and these are suitable for a variety of indications. All three contemporary techniques have demonstrated a wide range of fusion rates. This study reports a comparison of non-union rates of the 1^st metatarsophalangeal joint (MTPJ) with the current Memometal Anchorage™ dorsal plate system and the previous Hallu-fix™ and Charlotte™ systems.

Objectives. Cartiva synthetic cartilage implant (SCI) is licenced for use in management of symptomatic hallux rigidus in several countries including the UK. As for now, there are no independent comparative series for treatment of hallux rigidus utilising polyvinyl alcohol implants. Study design and methods. Patients at a single centre with symptomatic hallux rigidus who underwent Cartiva SCI implant procedure were identified. First metatarsophalangeal joint arthritis was radiographically graded according to the Hattrup and Johnson (HJ) classification. Pre-operative and post-operative patient-reported outcomes were evaluated using the Foot and Ankle Ability Measure (FAAM) activities of daily living subscale and the Manchester-Oxford Foot Questionnaire (MOXFQ). Results. 66 patients (19M, 47F) (43R and 23L) were followed up for an average of 14 months (min=2, max=36). 17 patients suffered from HJ2/moderate arthritis and 49 patients with grade HJ3/severe arthritis. Post-operative mean FAAM scores showed statistically significant improvement (p< 0.0001). Patients reported a 40% increase in functionality during activities of daily living. All 3 MOXFQ Domain scores improved significantly (p< 0.02). The Index score improved by 28 points (p< 0.0001). There was no correlation between length of follow up or age and PROMs (r=0.129). No statistical difference was demonstrated between sexes. However clinically, males and older patients exhibit better outcomes. There was a 89.4% patient satisfaction with the use of Cartiva. Conclusions. Our study shows excellent results with statistically significant improvements in functional outcomes, and promising short-term follow-up with low early revision rates. Pain in particular was significantly reduced. One third of patients developed post-operative stiffness requiring a manipulation under anaesthesia. Patient selection is key. Additional imaging may be required to assess sesamoid osteoarthritis. At 3 years the implant has demonstrated to be safe and efficacious in the management of hallux rigidus. Durability and survivability of the implant will continue to be studied in this cohort

Background. Hallux rigidus is a common condition characterised by first metatarsophalangeal joint (MTPJ) degeneration, pain and limited range of motion (ROM). The gold standard surgical treatment is arthrodesis, providing good pain relief but sacrifices ROM. Recently the Cartiva synthetic cartilage implant (SCI) has been utilised as an interpositional arthroplasty, aiming to reduce pain whilst preserving range of motion. Current evidence for Cartiva SCI is largely based on a single cohort with mixed outcomes. We sought to evaluate the clinical outcomes of Cartiva SCI compared to arthrodesis undertaken in our centre. Methods. Retrospective review of patients undergoing Cartiva SCI or arthrodesis for treating hallux rigidus was conducted. Preoperative arthritis was radiographically graded using the Vanore classification. Patient reported outcomes (PROMs) were assessed using EuroQol 5-dimension score (EQ-5D-5L) and Manchester-Oxford Foot Questionnaire (MOXFQ). Results. Between 2017 and 2020 there were 33 cases (17 Cartiva, 16 arthrodesis, mean age 59.0±9.9 years) with a mean follow up of 2.3 years. For the first MTPJ arthrodesis cohort, the MOXFQ domain scores were: Index 3.9±5.8, Walking/Standing 5.1±7.6, Pain 3.2±5.0, and Social Interaction 2.6±4.0. EQ-5D-5L Index score was 0.828±0.270 and the EQ-VAS was 72.5±23.3. For the Cartiva cohort, the MOXFQ domain scores were: Index 7.7±6.0, Walking/Standing 8.9±7.9, Pain 7.1±5.0, and Social Interaction 6.4±5.4. EQ-5D-5L Index score was 0.631±0.234 and the EQ-VAS was 74.8±20.8. There was no statistically significant difference between any MOXFQ domain or EQ-5D-5L scores. However, a negative trend in MOXFQ domains was identified for the Cartiva group, as well as a reoperation rate of 23.5%. Conclusions. The Cartiva SCI demonstrated no advantage over arthrodesis in PROMs, despite the presumed benefit of preserved ROM. A significant reoperation rate was also observed. Surgeons should be cautious in the use of this novel implant

Congenital hallux varus had been a well-described condition for many years before acquired hallux varus as a condition arising from bunion correction was not described until 1935. In that year, McBride discussed this potential problem when describing this as a potential problem from his described technique, identifying possible mechanisms to prevent the disorder from occurring. Authors such as Joplin and Kelikian echoed the concept in the early 1960's, spawning a series of corrective procedures. Miller brought this to common practice in 1975, describing the tendon imbalance seen across the precarious 1. st. MTP joint. The first metatarsophalangeal joint moves in the sagittal plane, dorsiflexion and plantarflexion only. Four intrinsic muscles stabilize the digit, with the abductor and adductor hallucis taking the lion share of this function. The abductor tendon actually functions primarily as a plantarflexor of the first metatarsophalangeal joint 83% of the time (Thompson) due to its primary plantar location. This fact, in combination with the pronation generally seen in severe bunion deformities, contributes to acquired hallux varus following bunion correction. Besides the obvious cause of over-correction of the metatarsal osteotomy creating hallux varus, imbalance of the tendon complex post-operatively can create an equally catastrophic circumstance. Hawkins demonstrated that severing the adductor tendon complex (the conjoined tendon) will not product hallux varus when the hallux is not rotated. However, in more severe hallux valgus, pronation of the hallux may be proportional to the deformity of the hallux itself. This rotational deformity places the insertions of the abductor (and medial insertion of the flexor brevis) more plantarward and lateral, increasing the valgus deformity. If the entire conjoined tendon is sectioned and the internal rotation deformity corrected the insertion of the contracted abductor moves medially, pulling the toe into varus. If the center of the base of the proximal phalanx is brought beyond the mid-point of the first metatarsal head, the extensor hallucis longus will bowstring, pulling the great toe into varus while creating a hallux flexus deformity. Finally, if the lesser toes are in varus and not corrected, this deforming force will create hallux varus following bunion correction with a lateral release. The message is clear: not all patients require a lateral release, and, if done, should be done with caution. Once present, correction can be difficult. Tendon transfers utilizing the extensor hallucis longus (Johnson) or extensor hallucis brevis (Myerson) only have beneficial effects in non-arthritic, mobile first metatarsophalangeal joints. In addition, if metatarsal deformity is not corrected, the deformity will recur. Thus, in many circumstances, arthrodesis of the first metatarsophalangeal joint becomes the treatment of choice, and is commensurate with a disappointed patient who underwent a primary bunion correction and was left with a fused great toe. This lecture will explore the above mechanism and salvage situations, in hopes of eliminating this unwelcomed outcome from your practice

Introduction. Orthopaedic and trauma surgeons not infrequently encounter the hallucal interphalangeal joint sesamoid (HIPJS) in irreducible traumatic dislocations. However, patients with the classic triad of plantar keratoma beneath a hyperextended interphalangeal (IP) joint associated with stiffness of the first metatarsophalangeal joint tend to present to podiatrists rather than orthopaedic surgeons. Methods. We present our experience with the HIPJS following first metatarsophalangeal joint (MTP1) arthrodesis in 18 feet of 16 women, aged 42 to 70 years old. Where CT scan was available, volume of the HIPJS was determined using Vitrea Software. Results. Two groups of patients were identified. Group 1 consisted of 12 feet in 11 women, who developed a painful keratoma beneath a gradually hyperextending IP joint of the great toe, at varying intervals (range 6 to 75 months) following MTP1 arthrodesis. Group 2 comprised 6 feet in 5 women who had undergone MTP1 arthrodesis but reported no symptoms in relation to an undetected and/or recognized, but unexcised HIPJS (range 15 to 97 months). We found no difference in average size of the HIPJS between Groups 1 and 2 (190.42 mm. 3. and 196.47 mm. 3. , respectively). Clinically, all toes had been fused in good position and no difference existed in the post-operative angle subtended by the proximal phalanx of the arthrodesed big toe with the first metatarsal between the 2 groups. A good outcome followed removal of metalwork and excision of the HIPJS in the symptomatic patients. Conclusion. Think of a HIPJS in the patient who presents with a painful plantar keratoma beneath a hyperextended interphalangeal joint following MTP1 arthrodesis. Do not rush into a Moberg osteotomy as this will only push the big toe higher against the toe-box. Consider prophylactic excision of a HIPJS prior to MTP1 arthrodesis

Aims. The aim of this study was to report a single surgeon series of consecutive patients with moderate hallux valgus managed with a percutaneous extra-articular reverse-L chevron (PERC) osteotomy. . Patients and Methods. A total of 38 patients underwent 45 procedures. There were 35 women and three men. The mean age of the patients was 48 years (17 to 69). An additional percutaneous Akin osteotomy was performed in 37 feet and percutaneous lateral capsular release was performed in 22 feet. Clinical and radiological assessments included the type of forefoot, range of movement, the American Orthopedic Foot and Ankle (AOFAS) score, a subjective rating and radiological parameters. . The mean follow-up was 59.1 months (45.9 to 75.2). No patients were lost to follow-up. Results. The mean AOFAS score increased from 62.5 (30 to 80) pre-operatively to 97.1 (75 to 100) post-operatively. A total of 37 patients (97%) were satisfied. At the last follow up there was a statistically significant decrease in the hallux valgus angle, the intermetatarsal angle and the proximal articular set angle. The range of movement of the first metatarsophalangeal joint improved significantly.. There was more improvement in the range of movement in patients who had fixation of the osteotomy of the proximal phalanx. Conclusion. Preliminary results of this percutaneous approach are promising. This technique is reliable and reproducible. Its main asset is that it maintains an excellent range of movement. Take home message: The PERC osteotomy procedure is an effective approach for surgical management of moderate hallux valgus which combines the benefits of percutaneous surgery with the versatility of the chevron osteotomy whilst maintaining excellent first MTPJ range of motion. Cite this article: Bone Joint J 2016;98-B:365–73

Hallux rigidus was first described in 1887. Many aetiological factors have been postulated, but none has been supported by scientific evidence. We have examined the static and dynamic imbalances in the first metatarsophalangeal joint which we postulated could be the cause of this condition. We performed a finite-element analysis study on a male subject and calculated a mathematical model of the joint when subjected to both normal and abnormal physiological loads. The results gave statistically significant evidence for an increase in tension of the plantar fascia as the cause of abnormal stress on the articular cartilage rather than mismatch of the articular surfaces or subclinical muscle contractures. Our study indicated a clinical potential cause of hallux rigidus and challenged the many aetiological theories. It could influence the choice of surgical procedure for the treatment of early grades of hallux rigidus

Minimally Invasive foot surgery remains controversial. Potential benefits include a reduced incidence of wound complications, faster return to employment and normal footwear. There are no studies published regarding the results of minimally invasive dorsal cheilectomy. Patients and Methods. Thirty eight patients with painful grade I hallux rigidus underwent dorsal cheilectomy between April 2006 and June 2010. Minimally invasive cheilectomy (MIC) was introduced in August 2009. AOFAS scores, satisfaction, return to normal shoes and employment were assessed. Results. Twenty two patients had open cheilectomy (OC) whilst 16 had MIC. Mean follow-up was 6 months for the MIC group and 35 months for the OC group. Mean AOFAS score was 75/100 (SD 17) in the MIC group and 70/100 (SD 18). Patients rated their satisfaction as 9.1/10 for MIC and 8.6/10 for OC. There was no significant difference in time to return to normal shoes (P = 0.32) or employment (P = 0.07). Two patients (one MIS, one OC) had a superficial wound infection which resolved with oral antibiotics. One patient had a first metatarsophalangeal joint fusion in the MIS group. Two patients in the OC group went on to have a first metatarsophalangeal joint fusion and one underwent joint resurfacing. Discussion. These results suggest MIC has comparable early results to OC. Larger studies are required to further establish the benefits of MIC. Conclusion. Minimally invasive dorsal cheilectomy seems to offer a safe alternative to open cheilectomy with promising early results. Patient satisfaction with this procedure is very high

It is recognised that as the severity of hallux valgus (HV) worsens, so do the clinical and radiological signs of arthritis in the first metatarsophalangeal joint. However, few studies specifically document the degenerate changes. The purpose of this study is to determine if intraoperative mapping of articular erosive lesions of the first MTP joint can be correlated to clinical and/or radiographic parameters used during the preoperative assessment of the HV deformity. Materials & Methods. We prospectively analysed 50 patients who underwent surgery between Jan 2009 & Jan 2010. Patients with a known history of previous first metatarsophalangeal joint surgical intervention, trauma, or systemic arthritis were excluded from analysis. Preoperative demographics and AOFAS scores were recorded. Radiographic measurements were obtained from weight bearing radiographs. Intraoperative evaluation of the first metatarsal head, base of the proximal phalanx, and sesamoid articular cartilage erosion was performed. Cartilage wear was documented using International Cartilage Research Society grading. Results. three patients did not have scoring or cartilage wear documentation carried out and were excluded. The mean age was 56 years. The mean hallux valgus angle was 31 degrees. The mean IMA was 15 degrees. The mean AOFAS score was 62. Patients with no inferomedial (IM) and inferolateral (IL) wear had significantly better AOFAS score than patients who had IM & IL wear (p < 0.05). Patients who had IM & IL wear had a significantly higher HVA (p < 0.05). There was a significant positive correlation between hallux valgus angle and AOFAS score. We also found correlation between sesamoid wear and AOFAS score and HV angle. Conclusion. we conclude that preoperative clinical and radiographic measurements can be used to predict the incidence and location of articular erosions in the 1st MTPJ and are helpful in the preoperative assessment of the HV deformity

We reviewed the outcome of distal chevron metatarsal osteotomy without tendon transfer in 19 consecutive patients (19 feet) with a hallux varus deformity following surgery for hallux valgus. All patients underwent distal chevron metatarsal osteotomy with medial displacement and a medial closing wedge osteotomy along with a medial capsular release. The mean hallux valgus angle improved from −11.6° pre-operatively to 4.7° postoperatively, the mean first-second intermetatarsal angle improved from −0.3° to 3.3° and the distal metatarsal articular angle from 9.5° to 2.3° and the first metatarsophalangeal joints became congruent post-operatively in all 19 feet. The mean relative length ratio of the metatarsus decreased from 1.01 to 0.99 and the mean American Orthopaedic Foot and Ankle Society score improved from 77 to 95 points. In two patients the hallux varus recurred. One was symptom-free but the other remained symptomatic after a repeat distal chevron osteotomy. There were no other complications. We consider that distal chevron metatarsal osteotomy with a medial wedge osteotomy and medial capsular release is a useful procedure for the correction of hallux varus after surgery for hallux valgus

Introduction. We aimed to retrospectively identify risk factors for delayed / non-union for first metatarsophalangeal joint fusion. Methods. Case notes and radiograph analysis was performed for operations between April 2014 and April 2016 with at least 3 months post-operative follow up. Union was defined as bridging bone across the fusion site on AP and lateral radiographic views with no movement or pain at the MTPJ on examination. If union was not certain, CT scans were performed. All patients operations were performed/supervised by one of three consultant foot surgeons. Surgery was performed through a dorsal approach using the Anchorage compression plate. Blinded pre-operative AP radiographs were analysed for the presence of a severe hallux valgus angle equal or above 40 degrees. Measurement intra-observer reliability was acceptable (95%CI:1.6–2.3 degrees). Smoking and medical conditions associated with non-union underwent univariate analysis for significance. Results. 73 patients, 9 male, 64 female with a mean age of 61 years (range, 29 to 81) comprised the patient group. Mean follow up time was 13 months for both union vs non-union groups (range 3 to 24 months). 7 patients were identified as non / delayed union (9.6%). All smokers healed (n = 17), age, diabetes, COPD and rheumatoid arthritis did not show significant associations with non-union. Pre-operative hypothyroidism (relative risk 6.9, p = 0.05) and severe hallux valgus (relative risk 9.9, p = 0.002) were significantly associated with non / delayed union. Conclusion. Although overall bone mineral density is unaffected, studies have demonstrated abnormal bone remodelling in patients with hypothyroidism which may account for this unexpected finding. A dorsally placed locking plate with a dorsal to plantar placed compression screw is at a biomechanical disadvantage to resist lateral force when trying to hold a corrected severe hallux valgus. These patient groups may benefit from supplementary fixation techniques

Background. Hallux rigidus is a degenerative condition of the first metatarsophalangeal joint (MTPJ) of the great toe, which can result in significant pain and stiffness. Treatment using joint replacement, either by means of hemiarthroplasty or total arthroplasty of the metatarsophalangeal joint is becoming an increasingly popular option for patients with severe disease. Aim. To evaluate mid-term functional and radiological outcomes of a widely used first generation resurfacing arthroplasty system in the treatment of hallux rigidus. Method. Prospective review of patients from 2009 onwards. All patients were operated on by the senior author using the same first generation hemiarthroplasty prosthesis (HemiCAP®, Arthrosurface, USA) and surgical technique. Radiological and clinical outcomes were assessed at 3, 6, 12 and 24 months post-operatively. Patients were assessed pre- and post-operatively on an outpatient basis for MTPJ range of motion as well as outcomes using AOFAS and visual analogue scale scores. Results. 20 prostheses in 19 patients over a two year period. Mean follow-up was 18 months (range 12–24). Mean AOFAS score improved from 38.66 pre-operatively to 74.93 at 12 months post-operatively. Mean VAS score improved from 9.95 pre-operatively to 4.05 post-operatively. There was radiological subsidence in one patient. 5 patients (26%) required revision to arthrodesis due to ongoing pain and stiffness. Conclusion. Despite significant improvements in functional scores and positive radiological outcomes in most patients, we have seen high revision rates with this first generation prosthesis due to ongoing pain and stiffness. Since this study, there has been a redesign of this implant with the addition of a dorsal flange, but the first generation prosthesis still remains in use. Following our results, we have discontinued our use of this product in favour of either the newer generation hemiarthroplasty or total arthroplasty system for patients with severe hallux rigidus