Despite multiple published reviews, the optimum method of correction and stabilisation of Blount's disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. This technique was developed to minimise cost in a context of limited resources. This study was conducted between 2016 and 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32tibiae) who had correction of late-onset tibia by proximal tibial osteotomy and Ilizarov external fixator. All cases were followed up to 2 years. The mean proximal tibial angle was 65.7° (±7.8) preoperatively and 89.8° (±1.7) postoperatively. The mean mechanical axis deviation improved from 56.2 (±8.3) preoperatively to 2.8 (±1.6) mm postoperatively. The mean femoral-tibial shaft angle was changed from – 34.3° (±6.7) preoperatively to 5.7° (±2.8) after correction. Complications included overcorrection (9%) and pin tract infection (25%). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity. This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities

Introduction. Temporary spanning fixation aims to provide bony stability whilst allowing access and resuscitation of traumatised soft-tissues. Conventional monolateral fixators are prone to half-pin morbidity in feet, variation in construct stability and limited weight-bearing potential. This study compares traditional delta-frame fixators to a circular trauma frame; a virtual tibial ring block spanned onto a fine-wire foot ring fixation. Materials and Methods. The two cohorts were compared for demographics and fracture patterns. The quality of initial reduction and the maintenance of reduction until definitive surgery was assessed by two authors and categorised into four domains. Secondary measures included fixator costs, time to definitive surgery and complications. Results. Fifty-six delta-frames and 48 circular fixators were statistically matched for demographics and fracture pattern. Good or excellent initial reduction was achieved in 51 (91%) delta-frames and 48 (100%) circular fixators (p=0.022). Loss of reduction was observed in 15 (27%) delta-frames and 3 (6%) circular fixators (p<0.001). Post-fixator dislocation occurred in five (9%) delta-frames and one (2%) circular fixator (p=0.147). Duration in spanned fixation was equivalent (11.5 and 11.6 days respectively, p=0.211). Three (5%) delta-frames and 12 (25%) circular fixators were used as definitive fixation. The mean hardware cost was £3,116 for delta-frames and £2,712 for circular fixators. Conclusions. Temporary circular fixation offers statistically superior intra-operative reduction and maintenance of reduction, facilitates weight-bearing and provides more opportunity as the definitive fixation. Circular fixation hardware proved to be less expensive and protected against further scheduled and unscheduled operations

Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially.

The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins.

The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture.

Introduction. The vast majority of orthopaedic surgeons use C-arm fluoroscopy in the operating theatre when building a circular external fixator. In the absence of previous research in this area, we hypothesised that the surgeon who builds a circular external fixator is exposed to a greater amount of radiation purely as a result of the presence of the metallic fixator in the x-ray beam. The aim of our study therefore was to investigate how the presence of a circular external fixator affects the radiation dose to the surgeon and the surgical assistant. Materials & Methods. A simulated environment was created using a radiolucent operating table, an acrylic lower limb phantom (below knee segment), various configurations of metalic circular external fixation, and a standard size C-arm image intensifier. The variables investigated were 1. the amount of metal in the beam 2. the orientation of the beam (PA vertical vs lateral) 3. the horizonal distance of the person from the beam (surgeon vs assistant) and 4. the vertical distance of the various body parts from the beam (e.g. thyroid, groin). In terms of radiation dose, we recorded two things : 1. the dose produced by the image intensifier 2. the dose rate at standardised positions in the operating theatre. The latter was done using a solid-state survey sensor. These positions represented both where the surgeon and surgical assistant typically stand plus the heights of their various body regions relative to the operating table. Results. The effect of the presence of the circular external fixator : all frame constructs tested resulted in a statistically significant greater radiation dose both produced by the image intensifier and received by the surgical team. The effect of the beam orientation : the PA (vertical) orientation resulted in a statistically significant greater radiation dose for the surgeon than did the lateral orientation, but made no difference for the assistant. The effect of horizontal distance from the beam : unsurprisingly, the surgeon (who was closer to the beam) received a statistically significant greater radiation dose than the assistant. The effect of vertical distance from the beam : for the surgeon, the dose received was highest at the level of the phantom leg / frame, whilst for the assistant there was no statistically significant difference for any level. Conclusions. To our knowledge, this is the first study investigating the radiation dose rate to the orthopaedic surgeon when building a circular external fixator. We found that the surgeon does indeed receive a ‘double whammy’ because the image intensifier puts out a greater amount of radiation plus the metalic frame scatters more of the x-ray beam. Whilst the amounts are relatively small, we think that it's important to quantify doses that orthopaedic surgeons receive to ensure optimal radiation practices

Introduction. Circular external fixators are fundamental to lower limb reconstruction, primarily in situations with a high risk of infection such as open fractures. During the Covid-19 pandemic, use of circular frames in our unit decreased, following departmental approval, due to resource management and in keeping with BOA guidelines as we opted to “consider alternative techniques for patients who require soft tissue reconstruction to avoid multiple operations”. These alternatives included the use of internal fixation (plate osteosynthesis and intramedullary nailing) as a measure to reduce the number of hospital attendances for patients and to conserve resources. This change in practice has continued in part following the pandemic with the increased use of internal fixation in cases previously deemed unsuitable for such techniques. We present our experience of this treatment strategy in the management of complex lower limb injuries, focusing on outcomes and consider the lessons learnt. Materials & Methods. Data of patients with complex lower limb injuries treated before, during and after the pandemic were collected from our in-house trauma database, theatre records and follow up clinics. The rationale for choosing other techniques over a circular frame, the type of alternative technique used, the cost of such alternatives, the need for soft tissue reconstruction, time to recovery, complications and amputation rates were compared among groups. Results. These data suggest comparable outcomes between circular frames and alternative techniques can be achieved. A notable reduction in the number of circular frames applied during the review period was observed. Furthermore, frame fixation was associated with more frequent outpatient review and the associated implications for resource management. Conclusions. Conclusion: The Covid-19 pandemic has posed great challenges to the Trauma and Orthopaedic community, forcing us to be flexible by adopting alternative treatment methods to traditional circular external fixation. These alternatives have proven feasible and potentially more cost effective, prompting their adoption in the post pandemic era. However, this change of practice is not without potential consequences and continued investigation is warranted

We have carried out a retrospective review of 20 patients with segmental fractures of the tibia who had been treated by circular external fixation. We describe the heterogeneity of these fractures, their association with multiple injuries and the need for multilevel stability with the least compromise of the biology of the fracture segments. The assessment of outcome included union, complications, the measurement of the functional IOWA knee and ankle scores and the general health status (Short-form 36). The mean time to union was 21.7 weeks (12.8 to 31), with no difference being observed between proximal and distal levels of fracture. Complications were encountered in four patients. Two had nonunion at the distal level, one a wire-related infection which required further surgery and another shortening of 15 mm with 8° of valgus which was clinically insignificant. The functional scores for the knee and ankle were good to excellent, but the physical component score of the short-form 36 was lower than the population norm. This may be explained by the presence of multiple injuries affecting the overall score

Hig energy fractures of the lower limb are often associated with tibial or femoral bone loss, skin exposition with vascular and nervous injuries (Gustilo et al.). The surgical procedure is a real challenge, consisting in a temporary stabilization of the fracture associated with a plastic and/or vascular reconstruction. Once the skin and vascular injuries are recovered, the orthopaedic surgeon can remove the temporary stabilization performing a circular external fixation with bone lengthening by using the “bifocal” (one site of metaphiseal corticotomy and one site of compression) or “trifocal” (two sites of metaphiseal corticotomy and one site of compression) technique. We use to do a “docking site” treatment when bone fragments are nearly in contact. Our experience indicates that circular external fixation, by using the Orthofix system, is a very useful and safe technique in the management of severe lower limb injuries. Our good clinical results lead us to suggest this surgical technique that allow to obtain a limb reconstruction, avoiding segment amputation

Purpose of Study. Bicondylar tibial plateau fractures are serious injuries to a major weight bearing joint. These injuries are often associated with severe soft tissue injuries that complicate the surgical management. This retrospective study evaluates the management of these high-energy injuries with the use of limited open reduction and fine wire circular external fixation. Methods. Between July 2008 and June 2012, 54 consecutive patients (19 females and 35 males) with high-energy tibial plateau fractures were treated at our tertiary level government hospital. All patients were treated with limited open reduction, and cannulated screw fixation combined with fine wire circular external fixators as the definitive management. The records of these patients were reviewed. Results. Forty-six patients met the inclusion and exclusion criteria. Thirty-six patients had Schatzker type-VI and ten patients had Schatzker type-V fractures. All fractures united without loss of operative reduction. No wound complications, osteomyelitis or septic arthritis occurred. Average Knee Society Clinical Rating Score was 81.6, translating to good clinical results. Minor pin tract infection was the most common complication encountered. Conclusion. Fine wire circular external fixation combined with limited open reduction and cannulated screw fixation consistently produced good functional results without serious complications. NO DISCLOSURES

Abstract. OBJECTIVES. To determine if force measured using a strain gauge in circular external fixation frames is different for 1) different simulated stages of bone healing, and for 2) fractures clinically deemed either united or un-united. METHODS. In a laboratory study, 3 similar Ilizarov frame constructs were assembled using a Perspex bone analogue. Constructs were tested in 10 different clinical situations simulating different stages of bone healing including with the bone analogue intact, with 1,3 and 50mm gaps, and with 6 materials of varying stiffness's within the 50mm gap. A Bluetooth strain gauge was inserted across the simulated fracture focus, replacing one of the 4 threaded rods used to construct the frame. Constructs were loaded to 700N using an Instron testing machine and maximum force during loading was measured by the strain gauge. Testing was repeated with the strain gauge replacing each of the 4 threaded rods in turn, with measurements being repeated 3 times, across all 3 frame constructs for all 10 simulated clinical situations (n=360). Force measurements between the situations were compared using a Kruskal-Wallis test (KW) and a post-hoc Steel test was used for multiple comparison against control (intact bone model). Additionally, a pilot study has been initiated to assess clinical efficacy of the strain gauge measurement in patients with circular frames. The strain gauge replaced the anterior rod across the fracture focus for each patient. Patients were asked to step on a weighing scale with their affected limb, and maximum weight transfer through the limb and maximal force measured in the frame were recorded. This was repeated 3 times and a mean ratio of force to weight through affected limb was calculated for each patient. The clinical situation at each measurement was designated as united or un-united by one of the senior authors for analysis. Force measurements between the situations were compared using a Wilcoxon-Mann-Whitney test. RESULTS. In the laboratory study, including all constructs with the strain gauge in all positions, a statistically significant relationship between model stability and force measured was identified (KW test for overall relationship p<0.0001). The largest force was measured in the model with a 50mm gap (median 170N, IQR 155–192, range 83–213) and the smallest in the intact bone model (median 3N, IQR 1–8, range 0–11). Multiple comparison testing found a significant difference between intact bone and all the unstable situations (p=0.002 or better). Examining initial results from our pilot clinical study, nine measurements were available in seven patients. Three of these were taken in patients with fractures yet to unite, six in patients where union has since been confirmed clinically. The median force measured was significantly greater where the fracture was not united (median 1.66 N/kg, range 1.07–1.99 vs 0.12 N/kg, range 0.05–0.73, p=0.02). CONCLUSIONS. This laboratory study demonstrates that force measurement may be different at different stages of healing, and although only limited data was available, a pilot clinical study showed a significant relationship between the force measured and clinical union of the patient's fracture. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Purpose of the study:. Is circular external fixation a safe and effective method of managing closed distal third tibia fractures. These fractures are conventionally treated with plaster casts, intramedullary nails or plate fixation. These treatment modalities have complication rates in the literature of up to 16% malunion, 12% non-union, and 17% deep infections. Description and Methods:. Retrospective review of 18 patients with closed distal third tibia fractures, with or without extension into the ankle joint, treated with circular fixator systems and minimal percutaneous internal fixation of the intra-articular fragment if required. Patients were followed up for time to union, malunion incidence as well as incidence of pin tract and deep infection. Distal third fractures which were extra articular or with simple intra articular extension were included. (AO 43 A, B1, C1, C2 + AO 42 in distal third) Patients with pilon fractures (AO 43 B2, B3 and C3) were excluded. Summary of results:. The average time to union in these patients was 16 weeks (11–33 weeks). The non-union rate was 11.1% in comparison to 12% with conventional treatment. The malunion rate was 0% compared to 16% with conventional treatment. The incidence of pin tract infection was 16.6%, but no deep infections were noted, whilst conventional treatment shows deep infection in up to 17%. Conclusion:. Circular external fixation is a safe and efficient option in the treatment of distal tibia fractures. The incidence of complications is significantly reduced in comparison to conventional treatment

Introduction. Distal tibial fractures are notoriously difficult to treat and a lack of consensus remains on the best approach. This study examined clinical and functional outcomes in such patients treated definitively by circular external fixation (Ilizarov). Patients and Methods: Between July 2011 and May 2016, patients with fractures extending to within 1 muller square of the ankle were identified from our prospective Ilizarov database. Existing data was supplemented by review of clinical records. Fractures were classified according to the AO/OTA classification. Functional outcome data, including general measures of health related quality of life (SF-12 and Euroqol) and limb specific scores (Olerud and Molander Score and Lysholm scores) had been routinely collected for part of the study period. Patients in whom this had not been collected were asked to complete these by post. Adverse events were documented according to Paley's classification of: problems, obstacles and complications. Results. 142 patients with 143 fractures were identified, 40 (28%) were open, 94 (66%) were intra-articular, 85 (59%) were tertiary referrals. 32% were type 1, 28%, type 2 and 40% type 3 AO/OTA severity. 139 (97%) of the fractures united (2 non-unions, 1 amputation and 2 delayed unions who remain in frames), at a median of 165 days (range 104 to 429, IQR 136 to 201). 62% united by 6 months, 87% by 9 months and 94% by 1 year. Both non-unions have united with further treatment. Closed fractures united more rapidly than open (median 157 vs 185 days; p=0.003) and true Pilon (43C3) fractures took longer to unite other fractures (median 156 vs 190 days; p<0.001). 34% of patients encountered a problem, 12% an obstacle and 10% a complication. Of the complications, 6 (4%) were minor, 5 (3.5%) major not interfering with the goals of treatment and 4 (3%) major interfering with treatment goals (including the 2 patients with non-union and 1 who underwent amputation as well as 1 significant mal-union). This will increase to 4% if the 2 delayed unions fail to unite. Overall 56% reported good or excellent ankle scores at last report, 28% fair and 16% poor. Closed, extra-articular and non-43C3 fractures had better functional outcome scores than open, intra-articular and 43C3 fractures respectively. Conclusions. This study demonstrates a high union and low serious complication rate, suggesting that external ring fixation is a safe and effective treatment for these injuries. *Judged best paper*

Introduction

Ilizarov fixators are reliant on tensioned fine wires for stability. The tension in the wires is generated using specific tensioning devices. Loss of wire tension over time may lead of loss a stability and complications. A series of in vitro experiments were undertaken to explore wire tensioner accuracy, the impact of fixation bolt torque and initial tension on loss of tension in ilizarov constructs under static and dynamic loads.

Purpose:. This study attempts to establish whether biomechanical manipulation through distraction can result in fracture union. Method:. A retrospective clinical audit of 15 patients with delayed or hypertrophic non-unions treated successfully with closed distraction in circular external fixation. Average time to union, complications and complication rates were also reviewed. Inclusion criteria: all patients with delayed or hypertrophic non-union, treated by closed distraction between 2004 and 2011. Results:. Fifteen patients included in the study. The average time to union was 188 days. The most common complication was local pin tract sepsis. The most serious complication was a broken fixation ring that needed replacement. Conclusion:. Biomechanical fracture strain is calculated by dividing the fracture gap distance by the change in the fracture distance i.e. FRACTURE STRAIN = DIFFERENCE IN L/L Hypertrophic non-union occurs when the fracture strain is more than 10 %. This formula shows that by increasing the fracture gap, the fracture strain will decrease This concept is contrary to the current practice of compressing the fracture. This study shows that distraction can be used to manipulate the biomechanical circumstances that dictate the development of fracture non-union. Furthermore ring fixators are ideal devices to use for biomechanical manipulation

Statement of Purpose. To compare the functional outcome of Distal Tibial Metaphyseal fracture treated with Circular frame compared vs. Locking Plate. Methods and Results. Distal Tibial Metaphyseal fractures were retrospectively identified over an 18 month period. Each fracture was assessed individually using radiographs. All paediatric, compound, tibial plateau and intra-articular fractures were excluded from the study. Other methods of fixation including intramedullary nailing were also excluded. The remaining fractures were assigned to either the circular frame fixation or the locking plate intervention group. Outcomes were assessed using radiographs for union dates and microbiology results for evidence of infection. Patients were followed up by postal questionnaires, which included a modified American Orthopaedic Foot and Ankle Score (AOFAS), the Olerud and Molander Score (O&M) and a custom questionnaire. The custom questionnaire asked about co-morbidities, smoking status and work days lost following surgery. After exclusions, 30 patients (Frame=15, Plate=15), were sent out questionnaires via post. We received completed questionnaires from 21 patients (Frame=11, Plate=10) giving us a response rate of 70%. Results show no difference in infection rates, skin necrosis, non-union or re-operation rates. There was also no significant difference in patient AOFAS and O&M scores at follow up. Conclusion. There is no significant difference in complications and functional Outcomes between locking plate fixation and circular frames in the treatment of distal Tibial Metaphyseal fractures

Introduction and Aims: We report a series of 41 corrections in 36 adult patients performed for complex deformities of the foot and ankle using circular external fixation, with a mean follow-up of 4.4 years. The foot and ankle deformities were 18 hindfoot equines, two forefoot equines, six hindfoot and forefoot equines, eight equinovarus, two equinovalgus, one heel varus, four combination of these deformities. All patients had associated proximal pathology. These included seven shortening (six tibia, one femur), eight deformities (seven tibia, one femur), eight non-union (five infected non-union), (14) combination of these pathologies. All required simultaneous correction. Method: We studied the aetiology, pathophysiology of injury, clinical and radiological evaluation, and the outcome of treatment. The patients’ mean age was 37 years (range 16–56). Thirty deformities were sequelae of severe lower limb trauma; the others were due to neurological, congenital and iatrogenic causes. In all patients, conventional surgical methods had failed to achieve correction and many of them were considered for amputation. We describe the operative strategy and technique. Results: The aim of foot and ankle surgery was correction of deformity and contractures in 28 instances, correction of deformity and ankle fusion in 11 instances, and correction of deformity and ankle distraction in two instances. Thirty patients underwent bony corrective osteotomies, nine foot and ankle, 20 tibia and fibulae, one femur. For each patient, specific treatment goals were delineated that were realistically achievable. There were (78%) good to excellent results, (14%) fair result and (8%) poor results, which resulted in below knee amputation. Conclusion: Circular external fixation offers a versatile and effective method of treatment of a variety of complex foot and ankle deformities. If foot and leg deformities coexist consider simultaneous correction. Fusion should be considered where muscular imbalance exists

Background:. Various surgical flaps have been described for the reconstruction of post traumatic soft tissue defects of the heel. These techniques are not all familiar to orthopaedic surgeons. The presented technique is based on the use of a reverse flow island sural flap combined with a circular external fixator. Material:. This presentation is a review of 8 cases performed between 2003 and 2012. Results:. All cases were males with an average age of 39 years (16–56) with a follow up period between 2 and 10 years. The soft tissue defects were located around the heel and Achilles tendon as a result of road traffic accidents involving motor cycles. Six patients had associated bony injuries of the foot and ankle related to the soft tissue defect. All flaps remained viable, and cover was easily achieved with direct closure. Three cases required debridement of subsequent superficial necrosis and additional split skin grafting. Although the flaps are insensate per design, there were no associated problems of late onset pressure ulcers. The circular fixation added the additional benefit of protection and easy access of the posterior flap during the post-operative period. Mild venous congestion was a temporary feature, of no long term consequence. Conclusion:. The sural fasciocutaneous flap is a useful adjunct for the treatment of complex soft tissue defects around the heel and ankle. The main advantages include simplicity of design and easy execution, avoids the need for complex microsurgical techniques and can be performed with simple loupe magnification, and thus realistically falls within the realm of the treating orthopaedic surgeon

Introduction

Schatzker V & VI tibial plateau fractures are serious life-changing injuries often resulting in significant complications including post-traumatic arthritis. Reported incidence of secondary TKA following ORIF of all tibial plateau fractures is 7.3% and 13% for Schatzker V & VI tibial. This study reports a 15-year single centre experience of CEF of Schatzker V & VI fractures including PROMs and incidence of secondary TKA. This study was approved by the local Institutional board.

Treatment of tibial plateau fractures Schatzker type V and VI or with soft tissues injuries is still remains under discussion. The purpose of this study is to evaluate the results of treatment with circular frame and closed reduction in 25 patients (15 males and 10 females) with tibial plateau fractures, with a mean age of 42 years old (20 – 76 years).

Five fractures were classified as Schatzker type II and III and 20 as type V and VI. Reduction was obtained in 22 cases under foot traction and in 3 arthroscopically. Bone grafts inserted through a hole (• 1 cm) in the inner cortex of the tibia metaphysis under fluoroscopy. Eight unstable knees needed bridging the joint for 4 weeks. In 2 cases a cannulated interfragmentary screw was used. Full weight bearing was allowed 3 months after injury when the device was removed.

Follow up ranged from 1 to 10 years (mean 5 years). All fractures were united and there was no infection. Full range of the knee motion was achieved in 23 patients while 2 needed an open arthrolysis. There were 2 malunions which were treated with one valgus osteotomy and one TKR. Asymptomatic arthritis appeared in 6 patients. According to Knee Society Score (KSS) the results were classified as excellent in 12, good in 8, fair in 3 and poor in 2 patients.

Circular frames are a satisfactory alternative method for the treatment of tibial plateau fractures either in severe soft tissues injuries or in very complex cases

31 cases of high-energy proximal tibial fractures were retrospectively analysed. The series included 22 cases of Schatzker VI and 9 cases of proximal tibial extraarticular fractures. There were 7 females and 24 males, with average age being 45years(26–94). There were 12 open fractures ( 1 Gustilo grade1, 10 grade 3b and one 3c); while 19 cases had Tcherne’s grade 2–3 injury. 4 patients developed compartment syndromes requiring fasciotomy. All fractures were treated with preliminary ligamentotaxis using a unilateral external fixator. In addition, Open fractures underwent radical debridement with the one case of 3c requiring vascular reconstruction. CT scan was then done to assess the joint incongruity ,anatomy of the fracture, and to aid in decision making. The fractures were then fixed using percutaneous techniques and a circular external fixator. Minimal open reduction was resorted to in cases with significant joint depression. In all, 26 cases were managed using percutaneous techniques alone while 5 required minimal open reduction and screw fixation. Bone grafting was done in 6 cases and 11 required a plastics procedure for soft tissue reconstruction. The results were assessed using the radiological Rasmussen’s criteria and the clinically using he IKSS knee score. At a mean follow-up of 31mths, the mean time to metaphyseal union was 18weeks (6–25weeks);. 28 patients had good to excellent clinical scores, while 3 had a fair result. The radiologic assessment graded 12 cases as excellent and 19 as good. Complications included 2 cases with flap edge necrosis, 2 with severe pin tract sepsis, 1 with proximal DVT and one case with septic arthritis.

We conclude that the above treatment protocol yields promising results, preserving good knee function without prejudicing future need for arthroplasty.