Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of surgical approach on gait kinetics and kinematics. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis.

Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardised implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance.

All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group.

Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question.

Background

Management of failed total ankle replacements (TAR) remains a difficult challenge. Ankle arthrodesis, revision TAR, debridement and amputation are all utilized as surgical options. The purpose of the study was to review a series of failed TAR surgically managed in our tertiary referral centre.

Introduction:

The Best Practice Tariff (BPT) for hip fractures was introduced in April 2010 to promote a number of quality markers, including surgery within 36 hours. We conducted an audit to see whether the introduction of the BPT has had an inadvertent adverse effect on delay to fixation of unstable ankle fractures.

Introduction:

In 2009 the Smart Toe implant was introduced as an option for lesser toe fusion in our department. The Smart Toe is an intramedullary device made from Nitinol, an alloy that can change shape with a change of temperature, expanding within the intramedullary canals of the proximal and middle phalanx to achieve fixation. The advantages of the Smart Toe are that patients are spared 6 weeks with K-wires protruding from their toes and there is no need for wire removal. We conducted a retrospective review of radiographic and clinical outcomes to assess the performance of this implant.

Introduction:

Recent published studies have examined the normal dimensions of the syndesmosis on CT. However, previous anatomical studies have shown variations of the articulating facets within the tibialae fibularis and may contribute to the false appearance of increased spacing within the syndesmosis. In this study, we measured and compared anterior and posterior distances of the distal tibiofibular(DTF) syndesmosis on MRI and CT imaging.

Full-thickness burns around the knee can involve the extensor mechanism. The gastrocnemius flap is well described for soft tissue reconstruction around the knee. We describe a method where a Whichita Fusion Nail¯ knee arthrodesis, combined with a medial gastrocnemius muscle flap was used to salvage the knee and preserve the lower leg following a full-thickness contact burn.

The gastrocnemius flap for wound coverage of an open knee joint was originally described in 1970 and remains the workhorse for soft tissue knee reconstruction. There are a number of local alternatives including the vastus lateralis, medialis and sartorius flap; and perforator flaps such as the medial sural artery perforator island flap and islanded posterior calf perforator flap, however many of these are unsuitable for larger defects.

Full-thickness burns around the knee can put the extensor mechanism at risk and subsequent rupture is a possible consequence. The gastrocnemius flap has been used to cover a medial knee defect with exposed joint cavity following a burn and also been used in post burn contracture release around the knee.

The primary indication for Wichita fusion nail is a failed total knee replacement. It allows intramedullary stabilization with compression at the arthrodesis site to stimulate bone union. With fusion rates reported up to 100% and low complication rates as compared to other methods of fusion, the technique has a useful role in limb salvage type procedures.

While use of the gastrocnemius flap in knee burns has been described before we believe this is the first time that this combination of techniques, namely knee arthrodesis with soft tissue reconstruction using a gastrocnemius flap, has been reported. Combining these procedures with a multidisciplinary approach provides a useful alternative leading to limb salvage and avoiding the need for an above knee amputation when extensor reconstruction is not possible.

Purpose: Medial compartment osteoarthritis (OA) is the most common primary osteoarthritis of the knee, but the treatment of this disease in young patients remains controversial. High tibial osteotomy (HTO), medial unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are all viable options. Gait analysis is one tool available to clinically assess knee kinematics, and may prove to be a good way of predicting functional outcomes of these different surgical procedures. The purpose of this study was to compare the knee kinematics, function, and quality of life of patients that underwent either a medial opening wedge HTO, UKA, or TKA for primary medial compartment OA.

Method: A matched prospective cohort study of patients between the ages of 45 and 65 who had undergone an HTO, UKA, or TKA for primary medial compartment knee OA was undertaken over a 3-year period. Primary outcome measures were gait variables, namely knee adduction moments, as measured through gait analysis. Secondary measures included quality of life (WOMAC), functional performance tests (six minute walk and timed-up-and-go), self-reported functional ability (LEFS), and general health (SF-36). Gait and functional performance tests were evaluated preoperatively and at 6, 12, and 24 months postoperatively. Self-reported quality of life, function and general health were assessed preoperatively and at 3, 6, 12, and 24 months post-operatively.

Results: Twenty HTOs, 19 medial UKAs, and 17 TKAs were matched for Kellgren-Lawrence grade of medial OA, age at surgery, and body mass index. Significant differences were observed between the three groups in step length and peak adduction moments at 24 months. Significant differences were observed in preoperative WOMAC pain and function scores, KOOS pain scores, and LEFS, but no significantly different outcome measures were observed postoperatively. Lateral Black-burne-Peel and modified Insall-Salvati ratios were the only significant radiographic differences observed between groups at 24 months.

Conclusion: To our knowledge, no gait analysis study exists comparing the medial opening wedge HTO to UKA or TKA. The results of this study suggest that most gait variables except step length and knee adduction moments are similar between groups. Moreover, except for patellar height, there were no major functional or radiographic differences between these groups.

Purpose: Simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction has been proposed as a treatment for patients with combined medial compartment knee osteoarthritis (OA) and ACL deficiency. Although goals of surgery are to correct malalignment, decrease knee joint load and enable continued participation in sports, few prospective studies evaluating these outcomes exist. Therefore, the objective of this study was to evaluate two-year changes in frontal plane alignment, dynamic knee joint load and self-reported function during sport after simultaneous HTO and ACL reconstruction.

Method: Thirty patients with varus alignment, medial compartment knee OA and ACL deficiency have undergone medial opening wedge HTO and hamstring tendon ACL reconstruction during a single operation. Full-length, standing AP radiographs (mechanical axis angle), dynamic knee joint loads (the peak external adduction moment about the knee during self-paced walking) and the Knee Injury and Osteoarthritis Outcome Scale (KOOS) were completed before and 24 months after surgery.

Results: Based on the 14 patients currently at 24.9 ± 1.67 months postop (12 males; age = 38.5 ± 7.5 yrs.; BMI = 29.5 ± 5.6, median Kellgren and Lawrence grade = 2), mechanical axis angle decreased significantly (p< 0.005) from −6.2 ± 3.63° to 0.29±1.94°. Despite a small (0.06 ± 0.10m/s), but significant (p< 0.05), increase in self-paced walking speed after surgery, the peak knee adduction moment decreased significantly (p < 0.001) from 2.96 ± 0.61 %BW*ht to 1.58 ± 0.48 %BW*ht [mean decrease = 1.38 %BW*ht (95% CI: 0.87 – 1.89)]. Each domain of the KOOS also improved significantly (p< 0.05), with the mean sports and recreation domain increasing (p=0.001) from 26.92 ± 24.29 to 66.54 ± 28.09 [mean increase = 39.62 (95% CI: 20.09 – 51.14)]. Data from 30 patients will be available at time of presentation.

Conclusion: Two-year outcomes after simultaneous medial opening wedge HTO and ACL reconstruction suggest this treatment results in substantial improvements in alignment, knee joint load and self-reported functioning during sport.

This randomized clinical trial compares fixed- and mobile-bearing total knee prostheses in terms of the patients’ clinical outcome parameters (Knee Society Clinical Rating, WOMAC, SF-12), range of motion and performance during gait analysis for level-ground walking. Our results show no significant differences in the clinical outcomes and gait performance of the fixed- and mobile-bearing total knee arthroplasties.

The purpose of this study was to compare the clinical outcomes and gait parameters of patients with a fixed-bearing or mobile-bearing total knee arthroplasty (TKA).

Fifty-five patients were entered into a prospective, randomized clinical trial comparing fixed- versus mobile-bearing TKAs (Genesis II, Smith & Nephew, Memphis, TN). From this patient population, fifteen fixed-bearing and fifteen mobile-bearing TKA patients were matched based on age, sex and BMI to undergo gait analysis. Patients performed trials of level-ground walking at a self-selected velocity while three-dimensional kinetic and kinematic data were collected.

The fixed-bearing and mobile-bearing TKA patient groups were comparable regarding Knee Society Clinical Rating (181 ± 22 versus 171 ± 28), WOMAC scores (7 ± 5 versus 9 ± 12), SF-12 and range of motion (121° ± 11° versus 125° ± 6°).

Patients with fixed- and mobile-bearing TKAs performed similarly in the gait analysis in terms of their velocity, percent weight acceptance in the operated versus the non-operated limb, peak flexion in stance and swing phases, the support moments and extension moments at the ankle, knee and hip. Decreased peak extension in the mid-stance and swing phases was observed in the operative limb versus the non-operative limb for both fixed- and mobile-bearing TKAs (P=0.02 and 0.04). Decreased peak extension was also observed during mid-stance and swing phases in the mobile-bearing TKAs versus the fixed-bearing TKAs (P=0.064 and 0.052).

Fixed-bearing and mobile-bearing TKAs perform similarly in terms of their clinical outcome measures and the kinetics and kinematics of level-ground walking.

Funding for this project obtained from Smith & Nephew, Memphis, TN.

The peak external knee adduction moment during walking gait has been proposed to be a clinically useful measure of dynamic knee joint load in patients with knee osteoarthritis. However, there is limited information about the reliability of this measure, or its ability to detect change. The test-retest reliability and sensitivity to change of peak knee adduction moments were evaluated in thirty patients with varus gonarthrosis. Indices of relative and absolute reliability were excellent (intra-class correlation coefficient = 0.85, standard error of measurement = 0.36 % BW*Ht), and the sensitivity to change following high tibial osteotomy was high (standardized response mean = 1.2).

To estimate the test-retest reliability, measurement error and sensitivity to change of the peak knee adduction moment during gait.

Thirty patients (44”11 yrs, 1.7”0.09 m, 87”20 kg, twenty males, ten females) with varus gonarthrosis underwent gait analyses on two pre-operative test occasions within one week, and on a third test occasion six months after medial opening wedge high tibial osteotomy. Three-dimensional kinematic and kinetic gait data were collected during self-paced walking and used to calculate the peak knee adduction moment.

An intraclass correlation coefficient of 0.85 (95%CI: 0.71, 0.93) indicated excellent relative reliability, and a standard error of measurement of 0.36 %BW*Ht (95%CI: 0.29, 0.49) indicated low measurement error. The peak knee adduction moment after surgery (1.66”0.72 %BW*Ht) was significantly (p< 0.001) lower than before surgery (2.58”0.72 %BW*Ht). A standardized response mean of 1.2 (95%CI: 0.77, 1.6) indicated the size of this change was large.

Based on 95% confidence levels, these results suggest the error in an individual’s peak knee adduction moment at one point in time is 0.70 % BW*Ht, the minimal detectable change in an individual’s peak adduction moment is 1.0 %BW*Ht, and it is sensitive to change following treatment.

The peak knee adduction moment during gait has appropriate reliability for use in studies evaluating the effect of treatments intended to decrease the load on the knee. When considering measurement error, the knee adduction moment is also appropriate for clinical use in evaluating change in individual patients.

Funding: CIHR, Arthrex Inc.

Aims: Surgical joint stabilisation can be achieved by capsular plication or thermal shrinkage. We hypothesised that there was no difference in mechanical and morphological properties after reduction of laxity in ligaments treated by either technique.

Methods: 30 skeletally mature female rabbits underwent either ‘thermal’ treatment, or ‘plication’ of their left medial collateral ligament (MCL). After 12 weeks convalescence, MCL complexes were procured from left and contralateral knees to undergo viscoelastic (creep) testing, quantitative transmission electron microscopy (TEM) and immunohistochemistry.

Results: Mean creep strain in both thermal (1.85 +/− 0.32%) and plicated ligaments (1.92 +/− 0.36%) was almost twice that of the control group (1.04 +/− 0.15%), although there was no difference between treatment modalities. However, collagen morphological parameters of all three groups were significantly different (p< 0.001). The thermal ligaments demonstrated predominantly small fibrils, whilst the plicated group displayed an intermediate distribution of heterogeneous fibrils (Fig. I). Immunohistochemistry followed by TEM revealed a random distribution of alpha-smooth muscle actin staining fibroblasts in both thermal and plicated groups.

Conclusion: Susceptibility to creep, and residual deformation after recovery, is similar after thermal shrinkage or plication, although inferior to intact ligaments. However, a different pattern of remodelling was revealed in the treatment groups. The plicated results suggest remodelling on a pre-existing fibrillar scaffold, yet the thermal group demonstrated histomorphometry similar to scar tissue, suggesting de novo synthesis. The absence of contractile myofibroblasts suggests that these cells may play an insignificant role in regulation of matrix tension during healing.

Surgical joint stabilisation can be achieved by ligamentous plication or thermal shrinkage, and as such, we hypothesized that there is no difference in mechanical and morphological properties after reduction of laxity in ligaments treated by either technique.

Methods: 30 mature female rabbits underwent either ‘thermal’ treatment of their left medial collateral ligament (MCL) using a bipolar radiofrequency probe, or plication with two 4/O non-absorbable sutures following division along its midsubstance and loaded positioning of the free ends. After 12 weeks convalescence, the animals were euthanised and MCL complexes were procured from left and contralateral knees to undergo viscoelastic (creep) testing, quantitative Transmission Electron Microscopy (TEM) and immunohistochemistry. The TEM data was quantified by two data procurement protocols; computational analysis and manual graticule.

Mean creep strain in both thermal (1.85 +/− 0.32%) and plicated ligaments (1.92+/−0.36%) was almost twice that of the control (1.04+/−0.15%), although there was no difference between treatment modalities. Similar findings were seen in the thermal (1.77+/−0.45%), plication (1.85+/−0.40%) and control groups (0.92+/−0.20%) for viscoplastic deformation. However, collagen morphological parameters of all three groups were significantly different (p< 0.001). The thermal ligaments demonstrated predominantly small fibrils, whilst the plicated group displayed an intermediate distribution of heterogenous fibrils. Immunohistochemistry followed by TEM revealed a sparse random distribution of alpha-smooth muscle actin staining fibroblasyts in both thermal and plicated groups. There was an insignificant difference in computational and manual procurement methods (p=0.84).

Susceptibility to creep, and residual deformation after recovery, is similar after thermal shrinkage or plication, although inferior to intact ligaments. However, the plicated results suggest remodeling on a pre-existing fibrillar scaffold, yet the thermal group demonstrated histomorphometry similar to scar tissue, suggesting de novo synthesis. The absence of contractile myofibroblasts suggests that these cells may have an insignificant role in regulation of matrix tension during healing.

Radio frequency (RF) electrothermal capsulorrhaphy has potential to enhance the results of arthroscopic stabilisation. However, early clinical reports have shown variable results when compared with open stabilisation. Numerous experiments have shown that the mechanical properties of thermally treated tissue are mechanically inferior to normal tissue during the early phase of remodelling. Ultimately, the real issue is how thermally treated tissue compares with tissue shortened by surgical plication, as would occur in an open procedure.

Using a validated technique the tibial insertion of the medial collateral ligament (MCL) of the knee was shifted proximally to induce abnormal laxity in 30 mature NZ White rabbits. Bipolar RF shrinkage was applied to the MCL in 15 rabbits, while in the remainder the MCL was surgically transected and plicated with a nonabsorbable suture. Unlimited mobilisation was permitted until euthanasia at 12 weeks after surgery. Bone-ligament-bone complexes were harvested and underwent low-load (viscoelastic) and high-load (tensile failure) analysis on an Instron mechanical testing apparatus. Specimens from intact MCLs were also collected for polarised light microscopy and transmission electron micrography. Quantitative analysis of collagen fibril morphology was performed on the TEM images.

There were no significant complications postoperatively. In both groups there was evidence of ligament healing and remodelling with a thin layer of scar tissue surrounding the MCL. Preliminary analysis has demonstrated that the cross-sectional area of the thermally treated MCLs was increased compared with the plicated MCLs. Somewhat surprisingly, the plicated group had greater vascularity and cellularity in the healing zone than the thermal group. Although crimp patterns remained disorganised in both groups, the collagen matrix appeared more organised in the thermal group.

These results support the concept that the thermally denatured matrix may act as a scaffold for rapid remodelling of the MCL, resulting in a larger mass of ‘scar’ tissue at the site of shrinkage. Since scar tissue following surgical transection is known to be materially inferior to normal ligament tissue, the increased volume in the thermal group may confer an advantage in structural terms. Mechanical testing is presently underway in our laboratory to determine this issue.

Although the epidemiology and pathomechanics of shoulder injuries in throwing athletes has been wellstudied, less is known about shoulder injuries in other sports where significant loads are carried by the upper limb. We evaluated 90 professional gymnasts who participated in a regular performance schedule during the millennium celebrations in the calendar year 2000. The gymnasts were divided into Group I (n=60) who were selected and trained for 18 months, and Group II (n=30) who were ‘fast-tracked’ through recruitment and training in the final six months before performance.

At the conclusion of the performance year, athletes were assessed using a subjective questionnaire, the SF-12 general health instrument, the Oxford instability questionnaire and the Constant score. They also underwent clinical examination, hypermobility scoring and fatigue testing.

Of those surveyed, 46% complained of pain in one or both shoulders, and the majority of these received nonoperative physical therapy during the year and were able to continue performing. Five patients (6%) had refractory pain, demonstrated signs of hypermobility, abnormal joint translation and positive relocation tests, often in the absence of symptomatic instability. All were in Group II, presented in the final six months of performance and required arthroscopic treatment for complex tears involving the anterior and superior labrum, including the biceps anchor.

These results indicate that the incidence of shoulder injury is very high among professional aerial gymnasts. The underlying cause is likely to be multifactorial in these hypermobile athletes, but the findings are consistent with the concept of cumulative microtrauma to the capsulolabral complex. Acute-on-chronic injury appears to be associated with complex labral pathology which presents with pain rather than with overt instability. Our observations suggest that training and performance schedules should be carefully monitored, incorporating extended preparation and recovery, in order to reduce the risk of shoulder injury. Further work on kinematics of the shoulder during dynamic loading of the weightbearing upper limb is required.