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

Distal interphalangeal joint (DIPJ) fusion using a k-wire has been the gold standard treatment for DIPJ arthritis. Recent studies have shown similar patient outcomes with the headless compression screws (HCS), however there has been no cost analysis to compare the two. Therefore, this study aims to 1) review the cost of DIPJ fusion between k-wire and HCS 2) compare functional outcome and patient satisfaction between the two groups. A retrospective review was performed over a nine-year period from 2012-2021 in Counties Manukau. Cost analysis was performed between patients who underwent DIPJ fusion with either HCS or k-wire. Costs included were surgical cost, repeat operations and follow-up clinic costs. The difference in pre-operative and post-operative functional and pain scores were also compared using the patient rate wrist/hand evaluation (PRWHE). Of the 85 eligible patients, 49 underwent fusion with k-wires and 36 had HCS. The overall cost was significantly lower in the HCS group which was 6554 New Zealand Dollars (NZD), whereas this was 10408 NZD in the k-wire group (p<0.0001). The adjusted relative risk of 1.3 indicate that the cost of k-wires is 1.3 times more than HCS (P=0.0053). The patients’ post-operative PRWHE pain (−22 vs −18, p<0.0001) and functional scores (−38 vs −36, p<0.0001) improved significantly in HCS group compared to the k-wire group. Literatures have shown similar DIPJ fusion outcomes between k-wire and HCS. K-wires often need to be removed post-operatively due to the metalware irritation. This leads to more surgical procedures and clinic follow-ups, which overall increases the cost of DIPJ fusion with k-wires. DIPJ fusion with HCS is a more cost-effective with a lower surgical and follow-up costs compared to the k-wiring technique. Patients with HCS also tend to have a significant improvement in post-operative pain and functional scores

Background Bony or cartilaginous ossicles appear at the plantar aspect of the interphalangeal joint of the great toe. The variation in pattern, prevalence and anatomic relationships of these structures is not clearly established in the literature, especially in a Caucasian population. Without this knowledge, pathology at this joint may be underestimated and surgical approaches may be poorly planned particularly as radiographs underestimate the incidence of ossicles at this joint. The aims of this study were to determine the incidence and pattern of ossicles at this joint and to establish their anatomical relationships in order to aid planning the approach for their excision. Method The left great toe interphalangeal joint was dissected in forty British Caucasian cadavers and the pattern of ossicles and their anatomic relationships were established. Results In 27.5% of specimens, there was no identifiable ossicle and in these cases, the tendon of flexor hallucis longus was adherent to the joint capsule. In the remaining specimens (72.5%), a bursa separated the tendon of flexor hallucis longus from the plantar joint capsule and ossicles were found embedded within the joint capsule. Over a half (52.5%) of the specimens had a single ossicle located centrally within the plantar capsule and the remaining 20% had two ossicles lying within the capsule. Conclusion This study shows that a large proportion of the population have either one or two bony or cartilaginous ossicles at this joint. In addition, the study has clarified the anatomy of this joint and shown that, when present, ossicles do not lie within the tendon of flexor hallucis longus and could be most safely approached from either a medial or lateral approach

Aims. The paediatric trigger thumb is a distinct clinical entity with unique anatomical abnormalities. The aim of this study was to present the long-term outcomes of A1 pulley release in idiopathic paediatric trigger thumbs based on established patient-reported outcome measures. Methods. This study was a cross-sectional, questionnaire-based study conducted at a tertiary care orthopaedic centre. All cases of idiopathic paediatric trigger thumbs which underwent A1 pulley release between 2004 and 2011 and had a minimum follow-up period of ten years were included in the study. The abbreviated version of the Disabilities of Arm, Shoulder and Hand questionnaire (QuickDASH) was administered as an online survey, and ipsi- and contralateral thumb motion was assessed. Results. A total of 67 patients completed the survey, of whom 63 (94%) had full interphalangeal joint extension or hyperextension. Severe metacarpophalangeal joint hyperextension (> 40°) was documented in 15 cases (22%). The median QuickDASH score was 0 (0 to 61), indicating excellent function at a median follow-up of 15 years (10 to 19). Overall satisfaction was high, with 56 patients (84%) reporting the maximal satisfaction score of 5. Among 37 patients who underwent surgery at age ≤ two years, 34 (92%) reported the largest satisfaction, whereas this was the case for 22 of 30 patients (73%) with surgery at aged > two years (p = 0.053). Notta’s nodule resolved in 49 patients (73%) at final follow-up. No residual triggering or revision surgery was observed. Conclusion. Surgical release of A1 pulley in paediatric trigger thumb is an acceptable procedure with excellent functional long-term outcomes. There was a trend towards higher satisfaction with earlier surgery among the patients. Cite this article: Bone Jt Open 2024;5(9):736–741

Introduction

Patients suffering from finger joint pain or dysfunction due to arthritis and traumatic injury may require arthroplasty and joint replacement. Single-part silicone-based implants remain the material of choice and most widely used option, although reports on their long-term clinical performance are variable. For trauma indications, patients have a high expectation of functionality necessitating the use of materials with high wear resistance and mechanical performance. A new proximal inter phalangeal (PIP) joint designed by Zrinski AG (Wurmlingen, Germany), comprising a self-mating carbon fibre reinforced polyetheretherketone (CFR-PEEK) coupling, may provide a suitable alternative. Here we describe the wear performance of the CFR-PEEK components in a PIP joint wear simulator and subsequent characterisation of the wear particles.

Osteoarthritis (OA) of the equine distal interphalangeal joint (DIPJ) is a common cause of lameness. MicroRNAs (miRNAs) from biofluids such as plasma and synovial fluid make promising biomarker and therapeutic candidates. The objectives of this study are (1) Identify differentially expressed (DE) miRNAs in mild and severe equine DIPJ OA synovial fluid samples and (2) Determine the effects of DE miRNAs on equine chondrocytes in monolayer culture. Synovial fluid samples from five horses with mild and twelve horses with severe DIPJ OA were submitted for RNA-sequencing; OA diagnosis was made from MRI T2 mapping, macroscopic and histological evaluation. Transfection of equine chondrocytes (n=3) was performed using the Lipofectamine® RNAiMAX system with a negative control and a miR-92a mimic and inhibitor. qPCR was used to quantify target mRNA genes. RNA-seq showed two miRNAs (miR-16 and miR-92a) were significantly DE (p<0.05). Ingenuity Pathway Analysis (IPA) identified important downstream targets of miR-92a involved in the pathogenesis of osteoarthritis and so this miRNA was used to transfect equine chondrocytes from three donor horses diagnosed with OA. Transfection was successfully demonstrated by a 1000-20000 fold increase in miR-92a expression in the equine chondrocytes. There was a significant (p<0.05) increase in COMP, COL3A1 and Sox9 in the miR-92a mimic treatment and there was no difference in ADAMTS-5 expression between the miR-92 mimic and inhibitor treatment. RNA-seq demonstrated miR-92a was downregulated in severe OA synovial fluid samples which has not previously been reported in horses, however miR-92a is known to play a role in the pathogenesis of OA in other species. Over expression of miR-92a in equine chondrocytes led to significantly increased COMP and Sox9 expression, consistent with a chondrogenic phenotype which has been identified in human and murine chondrocytes

Ten patients, who underwent treatment for complex fracture-dislocation of the proximal interphalangeal joint of finger and one patient for that of the interphalangeal joint of thumb with a modified pins and rubbers traction system, were reviewed to evaluate the clinical and functional results. Two patients had open fracture-dislocation, 5 had pilon fractures and 4 had fracture-dislocations. The system was modified to avoid rotation of the pins in the bone during joint mobilization, thus minimizing the risk of osteolysis due to friction of pins over the bone. Michigan hand scoring system was used for subjective assessment and range of motion at proximal and distal interphalangeal joints and grip strength for objective assessment. Average follow-up was 18 months (range 3 months to 28 months). The average normalised Michigan hand score was 86. Based on Michigan scores, overall hand function was rated excellent in 8 patients, good in 2 and poor in 1. Eight patients have returned to their original jobs. The average arc of flexion in the proximal interphalangeal joint was 85 degrees and in the distal interphalangeal joint it was 47 degrees. The average grip strength was 95 percent of the uninvolved side. Two patients developed minor pin site infection, which did not necessitate pin removal or any alteration in the treatment regime. There have been no cases of osteolysis, osteitis or osteomyelitis. This modification of pins and rubbers traction system has given very acceptable results with a low complication rate. It is light, cheap, effective and easy to apply

Normal digital flexion relies on flexor tendon pulleys to transmit linear muscular force to angular digital motion. Despite the critical role these pulleys play, there is a growing trend among surgeons to partially sacrifice or “vent” them during flexor tendon repair to improve surgical exposure. Although this new practice is reported to improve outcomes after flexor tendon repair, there is concern for the long-term effects of bowstringing, reduced finger range of motion (ROM) and altered tendon biomechanics. The objective of this study was to examine the effects of the application of a thermoplastic ring, acting as an “external” pulley, on flexor tendon biomechanics and finger ROM. We hypothesized that the application of an external thermoplastic ring would produce a centripetal force over the tendon to reduce bowstringing, improve finger ROM, and restore tendon loads following pulley venting. Twelve digits comprised of the index, long, and ring fingers from four cadaveric specimens were tested using a novel in-vitro active finger motion simulator. Servo-motors were used to generate motion. Loads induced by flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP), and joint range of motion were measured with each sequential sectioning of the A2, A3, and A4 flexor pulley, in comparison to a native healthy finger condition. At each finger condition, A2 and A4 external thermoplastic pulley rings were applied over the proximal phalanx and middle phalanx, respectively, to recreate A2 and A4 function. Results were recorded and analyzed using a one way repeated-measures ANOVA. Following venting of the A2, A3 and A4 pulley, proximal interphalangeal joint (PIPJ) ROM significantly decreased by 17.02 ± 8.42 degrees and distal interphalangeal joint (DIPJ) range of motion decreased by 17.25 ± 8.68 degrees compared to intact pulleys. Application of the external rings restored range of motion to within 8.14 ± 8.17 degrees at the PIPJ and to within 7.72 ± 8.95 degrees at the DIPJ. Similarly, pulley venting resulted in a 36% reduction in FDS load and 50% in FDP load compared to intact pulleys. Following application of the external rings, loads were almost restored to normal at 7% reduction for FDS load and 13% reduction for FDP load. Venting of flexor tendon pulleys significantly alters flexor tendon biomechanics and digit range of motion. The application of thermoplastic rings acting as external pulleys over the proximal and middle phalanges is an effective, inexpensive, non-invasive and reproducible therapeutic method to restore flexor tendon biomechanics and digit range of motion

Aim. Distal interphalangeal joint (DIPJ) arthrodesis is a well-accepted treatment of disease in the DIPJ of the hand. The ideal technique should be technically simple, quick, cheap, have minimal complications and yield a rapid return to function. Recent large published series report major complications of 11.1% and minor complications of 26% for this procedure. The study objective is to determine patient satisfaction and complication rates of DIPJ fusion using the Autofix screw (Small Bone Innovations, France), a smaller diameter headless compression screw. Methods. A standard questionnaire was devised to assess patients' overall satisfaction and complications related to the procedure. This data is compared to equivalent procedures published internationally. The patient's radiological records were reviewed to determine bone union at 7 weeks post-operation. Results. 39 fingers were fused in 29 participants. Mean follow up was 36 months (range 2–48 months). Patient satisfaction was above 90%. We had a major complication rate of 2.56%, a minor complication rate of 20.5%. There was a higher rate of complications in patients younger than 60 years of age. Discussion. Our technique for the insertion of the Autofix, headless compression screw is shown. It is a simple, quick and effective technique for the fusion of distal interphalangeal joints of all fingers; there is no ‘down-time’, and complication rates are superior to the largest series published in international literature. Furthermore, we demonstrated 100% union by 7 weeks in our patient sample. We attribute these results to 3 aspects of the procedure. 1) The Autofix screw is a smaller diameter screw than previously used for this procedure. 2) The screw generates significant compression across the fusion site. 3) We utilise bone graft as part of our routine management. NO DISCLOSURES

The authors report their results of “extension-block Kirschner wire fixation” for the treatment of mallet finger fracture. This technique should be considered in presence of a large bone fragment involving more than the 30% of the articular surface, with or without palmar subluxation of the distal phalanx. A modification of the extension-block technique is described reducing the fragment to 0° extension of the distal interphalangeal joint. The results confirmed the better outcomes of this modification, minimizing the postoperative extension lag at the distal interphalangeal joint. The Wehbe and Schneider method was used to classify the mallet finger fractures and the results were graded according to Crawford’s criteria (66,6% excellent and 33,4% good). The extension-block K wire technique, when properly applied, is a very helpful procedure avoiding the risks and complications of the open surgery and achieving a good indirect anatomical reduction of the fracture

A retrospective analysis was done on 20 cases of interphalangeal joint fusion of the great toe utilizing longitudinal cortical screw fixation. The purpose of this study was to present a series of interphalangeal joint fusion great toe done in both paediatric and adult patients using 3.5mm cortical screws. Most of the patients had interphalangeal joint fusion along with Jones transfer and other associated procedures with a mean follow up period of 19 months. Arthrodesis was successfully achieved in all the patients. No one had pain at the interphalangeal joint of the great toe. A literature review on interphalangeal joint arthrodesis was done and advantages of cortical screw fixation over other techniques have also been presented

Purpose of the study: Duplication of the thumb is the most common congenital anomaly of the first ray. The characteristic feature of type IV is the diversity of the clinical forms and the presence of certain complex forms particularly difficult to treat (Hung IVD). We propose a new procedure for reconstruction of IVD type thumb duplication. Material and method: This new procedure was used for thumb reconstruction in two boys with type IVD thumb duplication. Mean age at surgery was 10 months. Surgical technique. The future incisions were traced with a central skin resection removing the most hypoplastic nail entirely (generally the radial nail). At the bone level, a longitudinal osteotomy of the proximal phalanges was made over the entire length to remove the central part and obtain a width for the first phalanx comparable to that of the contralateral thumb. An oblique osteotomy was cut in the base of the distal phalanx of the ulnar hemithumb with resection of a radial corner. The same type of osteotomy was performed at the base of the distal phalanx of the radial hemithumb, but with preservation of the radial corner and resection of the rest of the radial thumb. The proximal hemiphalanges were sutured as were the bases of the distal phalanges. This produced automatic realignment and stabilisation of the interphalangeal joint without an ungueal intervention. Results: The three children were reviewed at 24, 18 and 12 months. The Horii score was good in all cases. Discussion: Type IVD duplications of the thumb are difficult to treat and may leave serious sequelae. Our technique is based on the principle of a central resection of the proximal phalanges associated with partial resection of the base of the distal phalanges. This enables realignment and stabilisation of the interphalangeal joint while avoiding the problem of ungueal dystrophy since only one nail is preserved. Our preliminary results are encouraging but must be confirmed with a longer term study

Introduction. Mallet toe is a flexion deformity of the distal interphalangeal joint of the lesser toe. It causes pain and callosity in the toe tip and the dorsum of the distal interphalangeal joint. Campbell refers to the “terminal Syme’s amputation” for this condition but the results of this have not previously been reported. Material and Methods. This is a retrospective review of 35 toes in 22 patients that underwent distal phalangectomy. Sixteen patients were aged over 70. Patients were interviewed by an independent observer regarding the pain relief, cosmetic acceptability and satisfaction with the procedure and were examined for callosity, stump tenderness, sensitivity and neuroma. Results. All patients were satisfied including pain relief and cosmetic acceptability at an average follow up of 4.6 years. One patient had mild wound infection. One patient had asymptomatic nail growth. No stump tenderness, sensitivity or neuroma was noted. Discussion and Conclusion. Coughlin reported a satisfaction rate of 89% and 86% following successful fusion and excision arthroplasty respectively. In this series all patients were satisfied. We feel that distal phalangectomy is an option in a selected group of elderly patients where pain relief and functional outcome is the priority

The rheological properties of synovial fluid (SF) are largely attributed to the presence of high molecular weight hyaluronic acid (HA). In normal SF, HA has been shown to be an anti-inflammatory molecule able to increase the viscosity and promote endogenous production of HA. The aim of the present report was to investigate the possible effect of HA concentration in rheological properties (elastic modulus, G´ and viscous modulus, G´´) of osteoarthritic equine SF. For this purpose, SF from intercarpal, metacarpophalangeal and distal interphalangeal joint was aspirated by aseptic arthrocentesis from 60 Warmblood horses. For determining HA concentrations in equine SF samples, a commercially available ELISA kit was used. Additionally, full rheological sample characterization was carried out with an AR-G2 rheometer (TA Instruments Ltd., UK) in order to measure the elastic G´ and viscous G´´ moduli, at horse's body (37.5 ºC) temperature. The ANOVA findings revealed statistically significant main effects of the factors Joint Type (p = 0.001), and main effects of covariates Age (p = 0.019) and HA (p < 0.001) on the mean values of logG” and logG' measurements. Interpreting the coefficients of the covariate HA, a positive correlation of HA was detected on the response logG” and logG' measurements. Collectively, these data illustrate the role of HA in equine pathological SF

Purpose: Two questions arise after metatarsophalangeal hallux arthrodesis: what are the 3D changes observed when walking on flat ground ? and is the arthrodesis compensation essentially at the talocrural or interphalangeal level ?. Material and methods: Our series included twelve patients (ten women and two men) mean age 60.7 years. Nine patients had unilateral arthrodesis and three bilateral arthrodesis. The optoelectronic exploration was conducted barefoot. The patients wore underclothes and 27 reflectors. A miniaturised reflector was placed on the distal end of each hallux. Three valid recordings were made. Results: General gait parameters and kinematic and kinetic values were unchanged (excepting nonsignificant maximal ankle dorsiflexion). On the arthrodesis side we observed: significant decline in propulsion force in the anteroposterior and vertical planes; significantly later heel lift-off; systematic anterior displacement of the ground reaction force of the metatarsophalangeal joint (not seen on the healthy side). Discussion: We propose a coherent explanation of these observations. The kinetics of balance movement under the head of the first metatarsal head is changed. When the foot is flat on the ground, as the ankle balance movement occurs, the weight of the body is transferred earlier and massively to the forefoot. While in the healthy foot this occurs under the metatarsophalangeal joint of the great toe, in arthrodesis patients body weight is transferred under the interphalangeal joint of the great toe. The balance movement of the interphalangeal joint of the great toe occurs when the ankle balance movement is terminated. The centre of the balance movement is more distal and heel lift-off tends to occur later. During the propulsion phase, the greater lever arm limits the propulsion force, explaining the lesser peak force observed on the arthrodesis side. Use of reflectors on the distal end of the hallux demonstrated that the arthrodesis compensation occurs essentially at the interphalangeal level, exposing this joint to greater risk of degeneration

Purpose of the study: Distal amputation of the long fingers with loss of dorsal or volar tissue may leave bone exposed requiring fingertip reconstruction to restore sensorial and tactile function. Several methods have been proposed for fingertip reconstruction. Among the methods the most widely used, thenar flaps predominate because of they are reliable and easy to perform but especially because of the very high-quality tissue function achieved. Material and methods: We report a series of 86 patients who presented an amputation of a long finger during a 4-year period (January 1998 to December 2002). A tenar flap was constructed within 24 of the operation. Mean patient age was 26 years; 80% of the accidents were occupational accidents; tissue loss was caused by sharp instruments in 72% of the cases; three-quarters of the cases involved the left non-dominant hand; the greatest damage was to the middle finger in 58% of cases. Loss of dorsal tissue was noted for 80% of the amputations. Trunk anesthesia was used for all patients to achieve cover with a thenar flap with a proximal pedicle in 80%. The flap was weaned from its blood supply at 18 days on average. Results: Outcome was assessed with three criteria at mean follow-up of one year. Subjectively, 80% of patients were satisfied with the operation. Permanent flexion of the distal interphalangeal joint was totally absent in 70% of patients. Using the British Medical Research Council, sensibility was scored S3 in 60% and S2 in 40%. Discussion: Described as early as 1926, the thenar flap is a novel method for achieving a cutaneous cover very close to the anatomic fingertip. Several drawbacks have nevertheless been formulated, namely permanent flexion of the distal interphalangeal joint, cutaneous sequelae at the donor site, and the «blind» nature of the flap which can be devoid of sensitivity. Analyzing the results obtained in our series showed that harvesting a flap in the middle of the thenar zone avoiding the medial region which raises the risk of a cheloid scar, the risk of distal interphalangeal flexion can be avoided by starting active-passive rehabilitation exercises as early as possible. At two months, the fingertip starts gaining sensitivity via the periphery. Conclusion: Thenar flaps are reliable, easy to perform flaps which provide an attractive solution to the reconstruction of long fingers

Rheumatoid arthritis is a whole body, lifetime incurable disease. The problems engendered by the disease process itself are highly individual, given that each set of problems that a patient has, the assessment and planning of surgery is a crucial aspect of the appropriate management of patients with polyarthritis. The presence of deformity does not necessarily indicate a problem of function, but one has to accept that certain deformities cause more problems than others and I draw your attention to swan neck deformity being relatively function-impairing and Boutonnière deformities less so. There is always a balance between the risk of surgery and the benefits to be obtained. The assessment is functional, anatomical, radiological, psychological, medical, financial and, finally, surgical. The functional assessment is intended to identify the problems a patient has in the activities of daily living, the anatomical assessment identifies the structures damaged which need to be prepared or replaced, the x-rays define the bone loss and, therefore, determine the limits of bony surgery, the psychological aspect identifies the patient’s capacity and willingness to be involved in often quite complex therapy programmes over a significant period of time. The medical problems of vasculitis and active disease are less frequent now but are contra-indications to surgery in the acute phases. The financial aspects are often under-rated. The costs of maintaining someone with significant disabilities is really quite great and, therefore, although surgery may only give some small improvement in function, it often has quite a significant impact on the degree of care and help an individual needs. Finally, the surgical assessment is to identify which structures and in which order. In terms of planning, the surgical priorities, described by Nalebuff, are:. 1 Nerves 2 Flexor tendons 3 Wrist 4 Thumb 5 MCP joints 6 Extensors 7 PIP joints 8 Distal Interphalangeal joints. Prolonged nerve compressions do not recover well; ruptures of flexor tendons are very difficult to treat; if the wrist is painful and unstable it inhibits any function that the hand might have; the thumb is 50% of hand function; metacarpophalangeal joints need to be stable and to flex approximately to 60° in order to be functional; extensor tendons need to glide and to be able to lift fingers away from the palm; the interphalangeal joints contribute greatly to the closing of grasp. The role of the therapist is pre-operatively to assess the patient appropriately for surgery, assessing all the aspects defined above and to ensure that the patient is compliant with the treatment post-operatively. The aphorism that 20% of the effort comes from the surgeon, 50% from the therapist and 20% from the patient is probably a fairly accurate representation of the importance of therapy post-operatively. Therapy must be planned, purposeful and progressive

Introduction and Objective. Zone 2 flexor tendon injuries are still one of the challenges for hand surgeons. It is not always possible to achieve perfect results in hand functions after these injuries. There is no consensus in the literature regarding the treatment of zone 2 flexor tendon injuries, tendon repair and surgical technique to be applied to the A2 pulley. The narrow fibro-osseous canal structure in zone 2 can cause adhesions and loss of motion due to the increase in tendon volume due to surgical repair. Different surgical techniques have been defined to prevent this situation. In our study, in the treatment of zone 2 flexor tendon injuries; Among the surgical techniques to be performed in addition to FDP tendon repair; We aimed to compare the biomechanical results of single FDS slip repair, A2 pulley release and two different pulley plasty methods (Kapandji and V-Y pulley plasty). Materials and Methods. In our study, 12 human upper extremity cadavers preserved with modified Larssen solution (MLS) and amputated at the mid ½ level of the arm were used. A total of 36 fingers (second, third and the fourth fingers were used for each cadaver) were divided into four groups and 9 fingers were used for each group. With the finger fully flexed, the FDS and FDP tendons were cut right in the middle of the A2 pulley and repaired with the cruciate four-strand technique. The surgical techniques described above were applied to the groups. Photographs of fingers with different loads (50 – 700 gr) were taken before and after the application. Proximal interphalangeal (PIP) joint angle, PIP joint maximum flexion angle and bowstring distance were measured. The gliding coefficient was calculated by applying the PIP joint angle to the single-phase exponential association equation. Results. Gliding coefficient after repair increased by %21.46 ± 44.41, %62.71 ± 116.9, %26.8 ± 35.35 and %20.39 ± 28.78 in single FDS slip repair, A2 pulley release, V-Y pulley plasty and Kapandji plasty respectively. The gliding coefficient increased significantly in all groups after surgical applications (p<0.05). PIP joint maximum flexion angle decreased by %3.17 ± 7.92, %12.82 ± 10.94, %8.33 ± 3.29 and %7.35 ± 5.02 in single FDS slip repair, A2 pulley release, V-Y pulley plasty and Kapandji plasty respectively. PIP joint maximum flexion angle decreased significantly after surgery in all groups (p<0.05). However, there was no statistically significant difference between surgical techniques for gliding coefficient and PIP joint maximum flexion angle. Bowstring distance between single FDS slip repair, kapandji pulley plasty and V-Y pulley plasty showed no significant difference in most loads (p>0.05). Bowstring distance was significantly increased in the A2 pulley release group compared to the other three groups (p<0.05). Conclusion. Digital motion was negatively affected after flexor tendon repair. Similar results were found in terms of gliding coefficient and maximum flexion angle among different surgical methods. As single FDS slipe repair preserves the anatomical structure of the A2 pulley therefore we prefer it as an ideal method for zone 2 flexor tendon repair. However, resection of FDS slip may jeopardizes nutrition to the flexor digitorum profundus tendon which weakens the repair site. Therefore the results must be confirmed by an in vivo study before a clinical recommendation can be made. Keywords: Flexor tendon; injury; pulley plasty; cadaver;

Aim. To examine the mid-term survival, clinical and patient reported outcomes of the silastic 1. st. metatarsophalangeal joint replacement for the treatment of end stage hallux rigidus. Methods. We reviewed 83 consecutive silastic arthroplasties performed in 79 patients for end stage hallux rigidus. There were 3 men and 76 women; mean age 63 years (range 45–78 years). No patient was lost to follow up. Average follow-up was 5.3 years (1.1–11.3 years). The EQ 5D–5L Health index, Manchester-Oxford Foot Questionnaire (MOXFQ), visual analogue scale (VAS) of pain and overall satisfaction rate (Likert scale) were collected for patient reported outcomes. Results. 2 patients required revision; 1 for early infection (2 months) and 1 for stem breakage (10 years 1 month). 5 patients reported lateral metatarsalgia, 2 patients reported neuropathic pain, 6 patients developed superficial infection which fully responded to oral antibiotics, and 1 patient developed interphalangeal joint pain. 2 patients died in the cohort. Pre-operative mean MOXFQ was 44, mean EQ5D Index was 0.564 and VAS was 6.97. At mean follow-up of 5.3 years, the mean MOXFQ was 12.7 (0–57), the mean EQ5D Index was 0.851 (−0.02–1) and the mean VAS was 1.67 (0–8). The mean range of motion was 35° (30° dorsiflexion and 5° plantarflexion). The overall satisfaction rate was 90.2%. The implant survival rate was 97.6%. Conclusions. The silastic big toe arthroplasty offers excellent clinical mid term survival and functional outcomes and could be considered as an attractive alternative to traditional fusion for end stage hallux rigidus

Aetiology and pathogenesis: The pathogenesis of boutonnière deformity, in the rheumatoid patient is usually quite clear, and is due to either a central slip failure or volar subluxation of the middle phalanx. This subluxation is seen more commonly in the patients with psoriatic arthropathy. The most common cause is a chronic synovitis of the proximal interphalangeal joint leading to attenuation of the sagital fibres between the central slip and the lateral bands and at a later stage disruption or attenuation of the central slip itself. Synovitis of the pip joint with separation of the lateral bands from the central slip allows the lateral bands to sublux forwards to lie anterior to the axis of rotation thus the intrinsics which extend the proximal and distal joints of the finger come to act as flexors of the proximal joint and continue to act as extensors to the distal joint. The patient will use the intrinsic muscles and they now have a flexion force upon the PIP joint and hyperextension force on the DIP joint, causing a boutonnière deformity. Volar subluxation of the middle phalanx draws forwards the lateral bands and defunctions the central slip creating the same imbalance. Scarring of the volar plate as is seen in volar plate injuries with the production of a pseudo-boutonnière deformity is sometimes seen in psoriatic arthropathy. In a boutonnière deformity the PIP joint is flexed and the DIP joint is extended. With the joints in this position, the origin and insertion of the intrinsic muscles are closer together, and as a consequence, with the passing of time, the muscles fibres will remodel in a shortened position, creating a lateral band tightness. Classification: Boutonnière deformity can be classified into four stages. Type I. The deformity is totally correctable passively, and there is full flexion of the DIP joint when the PIP joint is fully extended. The patient has a passively correctable flexion deformity of the PIP joint, and can actively flex the distal interphalangeal joint. The anatomical alterations are the following: elongation of the sagital fibres and volar displacement of the lateral bands but no secondary shortening of musculo-tendinous system. Type II. Flexion of the DIP joint is limited when the PIP joint is passively corrected. The patient cannot actively or passively flex the distal interphalangeal joint, when the PIP joint is passively corrected. Secondary shortening of the intrinsic/lateral band system because the intrinsics have remodelled in a shortened position. Type III. Stiffness of the PIP joint without joint destruction. There is no passive correction of the deformity but the joint surfaces are sound. The patient can not passively extend the PIP joint nor flex the DIP joint. Type IV. Stiffness of the PIP joint with joint destruction. In these cases, stiffness of the PIP joint is not only due to soft tissue remodelling but mainly to joint destruction. In this type, destruction of the joint cartilage should be added to the previously described anatomical deformities. X-ray examination is needed to confirm the diagnosis. Treatment: Boutonnière deformities, are both aesthetically and functionally less disabling than swan neck deformities because there is usually little loss of active PIP joint flexion. Some therapeutic options exist, and choosing the most appropriate surgical procedure will depend on the severity of the anatomical deformities which need to be corrected. Correction of PIP joint flexion. Mobilisation of the lateral bands and transposition of the lateral bands posterior to the axis of rotation of the PIP joint. Release of the volar plate of the PIP joint is often necessary because of secondary contracture. Improving active DIP joint flexion. The only way to restore loss of active DIP joint flexion is by performing a Dolphin tenotomy or formal lengthening of the conjoined lateral bands over the middle phalanx. Improving passive PIP joint extension. Passive extension of the PIP joint can usually be obtained by gentle manipulation and serial application of plaster of paris casts, as well as the use of a Capner (or armchair splint)the dorsal structures are usually quite thin and lax. If the joint can not be passively extended, a surgical release of the lateral bands is indicated,. Y-V plasty shortening of the central slip and extensor mechanism is usually necessary. A longitudinal incision at both sides of the central slip, allowing the lateral bands to displace dorsally during PIP joint extension with reefing of the lateral bands to the remnants of the central slip is needed in most cases. PIP joint arthroplasty. A PIP joint arthroplasty should be considered when the joint is destroyed. A radiological examination is essential in making the diagnosis, as many stiff PIP joints in flexion do not have their joint surfaces preserved because boutonnière deformities are often secondary to PIP joint synovitis. A full soft tissue procedure must be performed at the same time. DIP joint arthrodesis. Arthrodesis is only indicated for the treatment of uncorrectable deformity of the DIP joint with or without joint destruction, confirmed by radiological examination. The functional results of an arthroplasty are far superior for the treatment of a swan neck than a boutonnière deformity, because of the integrity of the extensor apparatus in the former, allowing for immediate postoperative motion. 7. PIP joint arthrodesis will be the treatment of choice if the finger presents a gross deformity with deteriorating function or failed surgery