Midterm Outcomes of a Synthetic Cartilage Implant for the First Metatarsophalangeal Joint in Advanced Hallux Rigidus.

BACKGROUND:: A prospective, randomized, noninferiority clinical trial of synthetic cartilage implant hemiarthroplasty for hallux rigidus demonstrated functional outcomes and safety equivalent to first metatarsophalangeal (MTP) joint arthrodesis at 24 months. We prospectively assessed safety and efficacy outcomes for synthetic cartilage implant hemiarthroplasty at a minimum of 5 years. METHODS:: Of 135 eligible patients from the original trial, 112 (83.0%) were enrolled (mean age, 58.2 ± 8.8 years; 87 females). Pain visual analog scale (VAS), Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL), and FAAM Sports subscales were completed preoperatively and 2 and 5 years postoperatively. Great toe active dorsiflexion, weightbearing radiographs, secondary procedures, and safety parameters were also evaluated. RESULTS:: At 24 months, 14/152 (9.2%) patients had undergone implant removal and conversion to arthrodesis. In years 2 to 5, 9/119 (7.6%) patients underwent implant removal and conversion to arthrodesis. At mean 5.8 ± 0.7 (range, 4.4-8.0) years' follow-up, pain VAS, FAAM ADL, and FAAM Sports scores improved by 57.9 ± 18.6 points, 33.0 ± 17.6 points, and 47.9 ± 27.1 points, respectively, from baseline. Clinically significant changes in VAS pain, FAAM ADL, and FAAM Sports were reported by 103/106 (97.2%), 95/105 (90.5%), and 97/104 (93.3%) patients, respectively. Patient-reported outcomes at 24 months were maintained at 5.8 years in patients who were not revised. Active MTP joint peak dorsiflexion was maintained. Ninety-nine of 106 (93.4%) patients would have the procedure again. CONCLUSION:: Clinical and safety outcomes for synthetic cartilage implant hemiarthroplasty observed at 2 years were maintained at 5.8 years. The implant remains a viable treatment option to decrease pain, improve function, and maintain motion for advanced hallux rigidus. LEVEL OF EVIDENCE:: Level IV, case series.

Treatment of first metatarsophalangeal joint arthritis using hemiarthroplasty with a synthetic cartilage implant or arthrodesis: A comparison of operative and recovery time.

BACKGROUND: First metatarsophalangeal joint (MTPJ1) hemiarthroplasty using a novel synthetic cartilage implant was as effective and safe as MTPJ1 arthrodesis in a randomized clinical trial. We retrospectively evaluated operative time and recovery period for implant hemiarthroplasty (n=152) and MTPJ1 arthrodesis (n=50). METHODS: Perioperative data were assessed for operative and anaesthesia times. Recovery and return to function were prospectively assessed with the Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) subscales and SF-36 Physical Functioning (PF) subscore. RESULTS: Mean operative time for hemiarthroplasty was 35±12.3min and 58±21.5min for arthrodesis (p<0.001). Anaesthesia duration was 28min shorter with hemiarthroplasty (p<0.001). At weeks 2 and 6 postoperative, hemiarthroplasty patients demonstrated clinically and statistically significantly higher FAAM Sport, FAAM ADL, and SF-36 PF subscores versus arthrodesis patients. CONCLUSION: MTPJ1 hemiarthroplasty with a synthetic cartilage implant took less operative time and resulted in faster recovery than arthrodesis. LEVEL OF EVIDENCE: III, Retrospective case control study.

Correlation of Hallux Rigidus Grade With Motion, VAS Pain, Intraoperative Cartilage Loss, and Treatment Success for First MTP Joint Arthrodesis and Synthetic Cartilage Implant.

BACKGROUND: Grading systems are used to assess severity of any condition and as an aid in guiding treatment. This study examined the relationship of baseline motion, pain, and observed intraoperative cartilage loss with hallux rigidus grade. METHODS: A prospective, randomized study examining outcomes of arthrodesis compared to synthetic cartilage implant was performed. Patients underwent preoperative clinical examination, radiographic assessment, hallux rigidus grade assignment, and intraoperative assessment of cartilage loss. Visual analog scale (VAS) score for pain was obtained preoperatively and at 24 months. Correlation was made between active peak dorsiflexion, VAS pain, cartilage loss, and hallux rigidus grade. Fisher's exact test was used to assess grade impact on clinical success ( P < .05). RESULTS: In 202 patients, 59 (29%), 110 (55%), and 33 (16%) were classified as Coughlin grades 2, 3, and 4, respectively. There was no correlation between grade and active peak dorsiflexion (-0.069, P = .327) or VAS pain (-0.078, P = .271). Rank correlations between grade and cartilage loss were significant, but correlations were small. When stratified by grade, composite success rates between the 2 treatments were nearly identical. CONCLUSIONS: Irrespective of the grade, positive outcomes were demonstrated for both fusion and synthetic cartilage implant. Clinical symptoms and signs should be used to guide treatment, rather than a grade consisting of radiographic, symptoms, and range of motion factors. LEVEL OF EVIDENCE: Level II, randomized clinical trial.

Does cutting a plaster window weaken its strength?

INTRODUCTION: A plaster window is usually created over a pressure area, or in some cases a wound or suture line. This can relieve pressure at the site, and provide an opportunity to change dressings, check on drainage, and inspect a wound or ulcer. There is concern that this can have an effect on its function to provide fracture stability, and weakens the plaster. The biomechanical effects of windowing on plaster strength were therefore investigated, as it has not previously been reported. METHOD: A laboratory study was undertaken to compare the bending, kinking and torsion loads withstood by standardised Plaster of Paris (POP), Softcast and Fibreglass casts compared to those with a 60×40mm window fabricated in the centre at clinically defined endpoints using an Instron machine. RESULTS: The addition of a window significantly weakened the load to failure of POP; Fibreglass, and Softcast by 23.1% (473.1N); 25.9% (401.8N), and 29% (146.6N) respectively, during the 4-point bending tests. During the 3-point kinking tests, load to failure was reduced by 38.5% (297.8N); 35.3% (146.9N), and 51.5% (103.8N) respectively. All tests were checked for consistency and carried out in a single orthogonal plane for ease of comparison. DISCUSSION: The addition of a 60×40mm window to a cast made up of POP, Fibreglass or Softcast weakens the cast load to failure by up to 51% against a 3-point loading force. Though windowing of casts is necessary in certain situations, we advise precautions such as adding further layers of plaster to the window site, keeping the window as small as possible, and advising the patient of the increased risk of weakening and failure of the plaster so that they can take more care.

Is softcast (3M) strong enough for potentially unstable paediatric forearm fractures?

INTRODUCTION: The majority of paediatric forearm fractures are treated using a circumferential splint, with prior manipulation as necessary. Plaster of Paris is often chosen for its ease of application, cost and proven reliability. Softcast is an alternative, providing a comfortable and water-resistant splint that can be removed without a plaster saw, and is in widespread use for immobilising buckle fractures. Softcast has not been recommended for acute unstable fractures. We established whether a Softcast splint could provide sufficient mechanical stability to control an unstable paediatric forearm fracture. METHODS: A laboratory study was undertaken to compare the 3 point (kinking) and 4 point bending, and torsion loads to defined clinical failure points withstood by standardised 4-wrap POP compared to Softcast splints with 6-wrap, 4 wrap and reinforced 4-wrap configurations. RESULTS: The load at clinically relevant failure of a 6-wrap Softcast forearm splint was 504N in 4 point bending, 202N in 3 point bending (kinking), and 11Nm in torsion (equalling 30.4%, 26% and 42.2% of the equivalent values for a circumferential 4-wrap POP). The 6-wrap Softcast was however stronger in all modes than a fibreglass-reinforced Softcast splint (previously recommended for acute fractures). Furthermore, the load to failure in all modes exceeds that which can be exerted by body weight in many paediatric patients. Softcast demonstrated complete recovery of its original shape on unloading, whereas POP was permanently deformed. 6-wrap Softcast splints were 4% lighter than POP. CONCLUSION: A 6-wrap Softcast splint provides adequate mechanical stability and protection for paediatric patients up to approximately 20kg, avoiding high-risk activities. The primary risk is not of fracture angulation and loss of position, but temporary indentation of the splint, causing discomfort or pain. Considering its ease of removal, Softcast may be preferable for younger paediatric patients. Its cost may be offset by reducing the number and duration of hospital visits.

Medial Gastrocnemius Flap for Reconstruction of the Extensor Mechanism of the Knee Following High-Energy Trauma. A minimum 5 year follow-up.

INTRODUCTION: The purpose of this study was to assess the medium-term results of reconstruction of the extensor mechanism using the medial gastrocnemius while also providing soft tissue coverage. MATERIALS AND METHODS: This retrospective review consisted of a consecutive series of four patients (age 28-40 years) with complex high energy traumatic injuries to lower extremity including both soft tissue loss and disruption of the knee extensor mechanism. The medial gastrocnemius rotational flap was used to reconstruct the patellar tendon and restore soft tissue coverage simultaneously. Range of motion and extensor lag; functional recovery was judged by return to work and sports activity. Validated measures included the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, and the modified Cincinnati Score. RESULTS: At the final follow up was 61.5 (57-66) months after reconstruction, the mean SF 12 physical component score ranged from 21.7 to 56.8 with a median of 55.3; the mental component from 42.8 to 60.7 with a median of 58.6. The KSS knee score ranged from 50 to 78 with a median of 68; the function score from 65 to 90 with a median of 85. The Oxford knee score ranged from 22 to 45 with a median of 33.5. The KOOS ranged from 28 to 82.7 with a median of 73.7 and the modified Cincinnati score from 38 to 82 with a median of 76.5. Knee range of motion ranged from 0 to 120°. Of the four patients three returned to working fulltime in their profession and returned to sports, including mountain biking and fitness training. CONCLUSIONS: For severe traumatic knee injuries with the combination of soft tissue defects and disruption of the extensor mechanism, the medial gastrocnemius flap provides an excellent reconstructive option to address both problems simultaneously. The results of this small case series support the use of this limb salvage technique.

A comparison of energy consumption between the use of a walking frame, crutches and a Stride-on rehabilitation scooter.

BACKGROUND: Following foot and ankle surgery, patients may be required to mobilise non-weight bearing, requiring a walking aid such as crutches, walking frame or a Stride-on rehabilitation scooter, which aims to reduce the amount of work required. The energy consumption of mobilising using a Stride-on scooter has not previously been investigated, and we aim to establish this. METHODS: Ten healthy volunteers (5 males:5 females) aged 20-40 years mobilised independently, then with each mobility device for 3min at 1km/h on a treadmill, with rest periods, whilst undergoing Cardio-Pulmonary Exercise Testing (CPET). Oxygen consumption (VO2), carbon dioxide excretion (VCO2), minute ventilation (MV), respiratory rate (RR) and pulse (HR) were measured at baseline, and after 3min of walking, without and with all 3 devices. Wilcoxon signed rank test was carried out to calculate significance with non-parametric values with Bonferroni correction. RESULTS: Three-point crutch mobilisation demonstrated significant increases in VO2 (0.7L), VCO2 (0.7L), MV (16.7L/min), pulse (24.8bpm) and RR (11.4breaths/min) compared to walking (p<0.05). Mobilisation with a frame produced significant (p<0.05) increases compared to walking; VO2 (0.7L), VCO2 (0.7L), MV (18.3L/min), pulse (35.9bpm), and RR (11.7breaths/min). Tests using the Stride-on demonstrated no significant increase compared to walking with regards to VO2 (0.1L; p=0.959), VCO2 (0.2L; p=0.332), pulse (10.1bpm; p=0.575), and RR (4.7breaths/min; p=0.633). The MV was significantly higher compared to walking (4.3L/min; p<0.05). DISCUSSION: Energy required for unit distance ambulation with a Stride-on device is similar to walking, and significantly lower than with a walking frame in single legged stance and three-point crutch mobilisation. This justifies its use as part of routine practice aiding early mobilisation of patients requiring restricted weight bearing or single legged weight bearing, especially in those with reduced cardio-pulmonary reserve as it is less physiologically demanding and does not rely on upper body strength.

Prospective, Randomized, Multi-centered Clinical Trial Assessing Safety and Efficacy of a Synthetic Cartilage Implant Versus First Metatarsophalangeal Arthrodesis in Advanced Hallux Rigidus.

BACKGROUND: Although a variety of great toe implants have been tried in an attempt to maintain toe motion, the majority have failed with loosening, malalignment/dislocation, implant fragmentation and bone loss. In these cases, salvage to arthrodesis is more complicated and results in shortening of the ray or requires structural bone graft to reestablish length. This prospective study compared the efficacy and safety of this small (8/10 mm) hydrogel implant to the gold standard of a great toe arthrodesis for advanced-stage hallux rigidus. METHODS: In this prospective, randomized non-inferiority study, patients from 12 centers in Canada and the United Kingdom were randomized (2:1) to a synthetic cartilage implant or first metatarsophalangeal (MTP) joint arthrodesis. VAS pain scale, validated outcome measures (Foot and Ankle Ability Measure [FAAM] sport scale), great toe active dorsiflexion motion, secondary procedures, radiographic assessment, and safety parameters were evaluated. Analysis was performed using intent-to-treat (ITT) and modified ITT (mITT) methodology. The primary endpoint for the study consisted of a single composite endpoint using the 3 primary study outcomes (pain, function, and safety). The individual subject's outcome was considered a success if all of the following criteria were met: (1) improvement (decrease) from baseline in VAS pain of ≥30% at 12 months; (2) maintenance of function from baseline in FAAM sports subscore at 12 months; and (3) absence of major safety events at 2 years. The proportion of successes in each group was determined and 1-sided 95% confidence interval for the difference between treatment groups was calculated. Noninferiority of the implant to arthrodesis was considered statistically significant if the 1-sided 95% lower confidence interval was greater than the equivalence limit (<15%). A total of 236 patients were initially enrolled; 17 patients withdrew prior to randomization, 17 patients withdrew after randomization, and 22 were nonrandomized training patients, leaving 152 implant and 50 arthrodesis patients. Standard demographics and baseline outcomes were similar for both groups. RESULTS: VAS pain scores decreased significantly in both the implant and arthrodesis groups from baseline at 12 and 24 months. Similarly, the FAAM sports and activity of daily living subscores improved significantly at 12 and 24 months in both groups. First MTP active dorsiflexion motion improvement was 6.2 degrees (27.3%) after implant placement and was maintained at 24 months. Subsequent secondary surgeries occurred in 17 (11.2%) implant patients (17 procedures) and 6 (12.0%) arthrodesis patients (7 procedures). Fourteen (9.2%) implants were removed and converted to arthrodesis, and 6 (12.0%) arthrodesis patients (7 procedures [14%]) had isolated screws or plate and screw removal. There were no cases of implant fragmentation, wear, or bone loss. When analyzing the ITT and mITT population for the primary composite outcome of VAS pain, function (FAAM sports), and safety, there was statistical equivalence between the implant and arthrodesis groups. CONCLUSION: A prospective, randomized (2:1), controlled, noninferiority clinical trial was performed to compare the safety and efficacy of a small synthetic cartilage bone implant to first MTP arthrodesis in patients with advanced-stage hallux rigidus. This study showed equivalent pain relief and functional outcomes. The synthetic implant was an excellent alternative to arthrodesis in patients who wished to maintain first MTP motion. The percentage of secondary surgical procedures was similar between groups. Less than 10% of the implant group required revision to arthrodesis at 2 years. LEVEL OF EVIDENCE: Level I, prospective randomized study.

Do split paediatric forearm POP casts need to be completed? A biomechanical study.

INTRODUCTION: Displaced paediatric forearm fractures are most often treated by manipulation under anaesthetic, followed by the application of a circumferential Plaster of Paris (POP) splint. Some surgeons choose to split the cast in order to facilitate immediate "spreading" with minimal distress to the patient, should the distal limb become compromised. Usually however, this does not occur, and the cast is completed at a later visit to the plaster room. Time, money and inconvenience could be saved if this modification was not necessary, and the final plaster would be lighter. OBJECTIVE: To establish whether the mechanical properties of a split POP are sufficient to stabilise a forearm fracture, and protect the patient from further injury. MATERIALS AND METHODS: The repeatability of all tests was established on control samples before undertaking the trial. 42 standardised 8 layer POP cylinders of appropriate dimensions were fabricated, of which 21 were split longitudinally. The splints were subjected to non-destructive tests in 4-point bending (Bending), 3-Point Kinking (kinking) and torsion modes, and the load at clinically relevant end-points was recorded. These simulated the deformity at which the splint no longer provided adequate stability and alignment, or at which the wearer was no longer protected. The splints were then loaded to destruction to establish the mode of ultimate failure. RESULTS: The mean loads at the clinical end points for split POP splints were: 1375N in Bending, 544N in Kinking and 12 Nm in Torsion (equalling 67.3%, 70.4% and 47.4% of the equivalent values for a circumferential splints). Loads were in excess of body weight for most paediatric patients. After ultimate failure, the proportion of casts that became unstable was similar (44% of full casts and 50% of split casts). CONCLUSION: Split POP splints which have not been spread, provide adequate stabilisation and protection of paediatric forearm fractures, and do not routinely require completion.