Matthew Welck

3D Biometrics for Hindfoot Alignment Using Weightbearing CT

Background: Hindfoot alignment on 2D radiographs can present anatomical and operator-related bias. In this study, software designed for weightbearing computed tomography (WBCT) was used to calculate a new 3D biometric tool: the Foot and Ankle Offset (FAO). We described the distribution of FAO in a series of data sets from clinically normal, varus, and valgus cases, hypothesizing that FAO values would be significantly different in the 3 groups. Methods: In this retrospective cohort study, 135 data sets (57 normal, 38 varus, 40 valgus) from WBCT (PedCAT; CurveBeam LLC, Warrington, PA) were obtained from a specialized foot and ankle unit. 3D coordinates of specific anatomical landmarks (weightbearing points of the calcaneus, of the first and fifth metatarsal heads and the highest and centermost point on the talar dome) were collected. These data were processed with the TALAS system (CurveBeam), which resulted in an FAO value for each case. Intraobserver and interobserver reliability were also assessed. Results: In normal cases, the mean value for FAO was 2.3% ± 2.9%, whereas in varus and valgus cases, the mean was −11.6% ± 6.9% and 11.4% ± 5.7%, respectively, with a statistically significant difference among groups (P < .001). The distribution of the normal population was Gaussian. The inter- and intraobserver reliability were 0.99 +/- 0.00 and 0.97 +/-0.02 Conclusions: This pilot study suggests that the FAO is an efficient tool for measuring hindfoot alignment using WBCT. Previously published research in this field has looked at WBCT by adapting 2D biometrics. The present study introduces the concept of 3D biometrics and describes an efficient, semiautomatic tool for measuring hindfoot alignment. Level of Evidence: Level III, retrospective comparative study.

Evaluation of the 1st metatarso-sesamoid joint using standing CT — The Stanmore classification

BACKGROUND Little is understood about the role that relative sesamoid displacement and chondral wear have on outcome after hallux valgus (HV) surgery. All existing methods to evaluate relative sesamoid displacement have limitations and furthermore, there have been no radiographic studies evaluating metatarso-sesamoid joint wear. Standing CT scan circumvents many of the existing problems in evaluation of relative sesamoid displacement, and also enables the first radiographic study assessing metatarso-sesamoid joint wear. METHODS Fifty feet (in 43 patients) with symptomatic HV (Group A) were compared with a control group of 50 feet (50 patients) (Group B). All images were standardised to enable reproducible measurements. The hallux valgus angle, Intermetatarsal angle, sesamoid rotation angle, sesamoid position and metatarso-sesamoid joint space were measured in all patients. RESULTS The intra and inter-observer reliability correlation showed that the standing CT assessment of sesamoid position (1.000), rotation (0.991) and metatarso-sesamoid joint space (0.960) were highly reproducible. There was a highly significant difference (p<0.0001) in sesamoid position, sesamoid rotation and metatarso-sesamoid joint space between Group A and Group B. CONCLUSIONS Standing CT has been shown to be a reproducible and accurate method of assessing the relative sesamoid displacement and metatarso-sesamoid joint space narrowing. The results have been used to propose a novel standing CT based classification of hallucal sesamoids, considering the degree of displacement and wear. This classification may ultimately facilitate research to provide new insight into the effect relative sesamoid displacement and chondral wear have on outcomes from hallux valgus surgery.

Pseudogout Associated Hip Pain in a Patient with HIV Infection.

HIV infection is a global pandemic, currently affecting approximately 77,000 people in the UK and 33 million people around the world. The infection has widespread effects on the body and can involve the musculoskeletal system. It is therefore important that orthopaedic surgeons are aware of the condition and its sequelae. We present the case of a 46-year-old man with a 10-year history of HIV who presented with acute hip pain, difficulty weight-bearing, and constitutional symptoms. Following radiological, microbiological, and serological tests a diagnosis of pseudogout was established following microscopic analysis of the hip joint aspirate. The patients symptoms resolved completely following the joint aspiration and NSAID therapy. Studies have shown a relationship between HIV infection and gout. The virus has also been linked to osteonecrosis, osteopenia, bone and joint tuberculosis, and septic arthritis from rare pathogens. However, it is difficult to fully ascertain whether these conditions are related to the HIV infection itself or the HAART (highly active antiretroviral therapy). There are no previously reported cases of HIV-infected patients with pseudogout. The case is discussed with reference to the literature.

The effects of weight bearing on the distal tibiofibular syndesmosis: A study comparing weight bearing-CT with conventional CT

BACKGROUND Syndesmotic injures are common and weight bearing imaging studies are often advocated to assess disruption. Although studies have examined the anatomical relationship between the fibula and incisura, the effect of weight-bearing on the syndesmosis has not been well reported. We characterise the changes which occur at the syndesmosis during weight-bearing. METHODS In this retrospective review we analysed the position of the fibula at the syndesmosis in a cohort of patients who underwent both non-weight-bearing and weight-bearing CT scans. The relative position of the fibula to the incisura was analysed to determine translation and rotation in the axial plane. RESULTS 26 patients were included. Comparison of measurements revealed statistically significant differences between groups which indicated that on weight-bearing the fibula translated laterally and posteriorly, and rotated externally with respect to the incisura. CONCLUSIONS This is the first study to measure the differences in position of the syndesmosis during weight-bearing in a population of patients that have undergone both weight bearing and non weight bearing CT. Our study confirms that weight-bearing results in lateral and posterior translation, and external rotation of the fibula in relation to the incisura and our findings should help in future studies looking at the effect of weight bearing on syndesmotic pathology.

Gastrocnemius tightness: A population based observational study

BACKGROUND Gastrocnemius tightness is believed to be associated with multiple musculoskeletal pathologies such as back pain, plantar fasciitis and metatarsalgia. Although surgical treatment of gastrocnemius tightness is gaining popularity the objective definition of a gastrocnemius contracture has not been determined. The aim of our study was therefore to quantify gastrocnemius tightness in a normal population. METHODS Adult participants with no obvious foot and ankle pathology were recruited. Gastrocnemius tightness was quantified using a weightbearing lunge test. Maximal ankle-foot dorsiflexion was measured on participants with the knee in full extension and flexed to 20° using a digital inclinometer. The ankle-foot dorsiflexion index or ADI (difference in ankle dorsiflexion with the knee extended and flexed) was calculated. The ADI values were plotted on a histogram to identify the distribution of values and were compared according to participant demographics. RESULTS 800 limbs from 400 participants were examined. There was a wide distribution of absolute values of maximal ankle-foot dorsiflexion ranging from 8 to 52°. The ADI ranged from 0 to19° and approximated to a normal distribution. The mean ADI was 6.04±3.49° and was positively correlated with age (r=0.132, P<0.001) and negatively correlated with physical activity (r=-0.88, P=0.015). CONCLUSION(S) Our study is the first to quantify gastrocnemius tightness in a large healthy adult population with differences observed by age and physical activity. We have defined an easy and reproducible weightbearing test that can be used in both research and clinical settings. The majority of the population have some degree of gastrocnemius tightness and values of ADI greater than 13° (>2 SD of the mean), as measured by the lunge test, may be considered abnormal.

Pigmented Villonodular Synovitis of the Foot and Ankle: A Tertiery Referral Centre Experience

Category: Other Introduction/Purpose: Pigmented Villonodular Synovitis (PVNS) is a benign but potentially locally aggressive condition, that results in an increased proliferation of synovium, causing villous or nodular changes of synovial-lined joints and tendon sheaths. The estimated incidence of PVNS is 1.8 new cases annually per million people, of which 2.5% occur in the foot and ankle, reflected by the limited reports of PVNS in the foot and ankle literature. We present our clinical experience of 76 patients presenting with PVNS about the foot and ankle. Methods: Patients with PVNS of the foot and ankle were identified from our tertiary referral hospital patient database from 2007 to 2017. The case notes were carefully reviewed to analyse the clinical, radiological, and histopathological features and to investigate their clinical behaviour, management and the factors influencing recurrence. Results: 76 patients were identified (32 male, 44 female) with a mean age of 39 years and mean follow-up of 5 years. The majority of cases were of localised, nodular PVNS (52%, 40/76) with the diffuse PVNS cases (48%, 36/76) presenting most commonly in the hindfoot. The most common presentation was of a swelling/lump (78%- 62/79), of which pain was an associated feature in 11% (7/62) and restricted range of motion a feature in 10% (6/62). Osteoarthritic change and cortical erosions were more commonly associated with diffuse PVNS. All patients underwent open synovectomy with a recurrence rate of 11% (7/76), all of which were the diffuse type. In those cases where synovectomy was paired with arthrodesis of the joint, there were no cases of recurrence (12%,9/76). Conclusion: We present our tertiary referral experience of PVNS in the foot and ankle as the largest series in the foot ankle ankle literature to date. A high index of suspicion is required in diagnosing PVNS. Nodular PVNS appears more common in the foot whereas diffuse PVNS more common in the ankle and hindfoot. Open synovectomy yields low recurrence rates. Although theorised, there is insufficient evidence to establish whether concurrent arthrodesis of the affected joint reduces risk of recurrence.

Tibiotalocalcaneal Arthrodesis Using a Straight Intramedullary Nail: A Weight Bearing CT Study

Category: Hindfoot Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis using a hindfoot intramedullary nail has been shown to be a safe and reliable technique in patients with severe ankle and hindfoot disease. There is debate about the use of straight nails versus curved nails. Proponents of the curved nail argue that straight nails predispose to greater risk of lateral plantar nerve injury, poor calcaneal bone purchase and inability to maintain satisfactory hindfoot valgus alignment. However, the subtalar joint is a condyloid joint enabling rotation of the talus on the calcaneum to create varus/valgus position of the calcaneal tuberosity. We present a clinical series of patients undergoing TTC fusion using a straight nail assessed by clinical and radiological outcomes to establish whether theoretical risks of straight nails are reflected in clinical practice. Methods: This single centre, retrospective study of prospectively collected data on a sequential series of patients to undergo TTC fusion, with pre and post-operative weight bearing CT imaging. Data was collected on indication for procedure, co-morbidities, post-operative complications, union rate as well as clinical scores, EQ5D and MOXFQ. Weight bearing CT imaging was analysed using the validated TALUS™ (torque ankle lever arm system) method on weight bearing CT, providing calcaneal offset, hindfoot angle and hindfoot alignment. These were used as markers of hindfoot alignment. Results: 65 patients (37 males, 28 females) were included in the study, with an average age of 57 years. Average follow-up was 20 months. Indications for TTC fusion included Charcot arthropathy, talar avascular necrosis, post traumatic arthritis and non-union of previous arthrodeses. Union rate was 91% (59/65). Overall complication rate was 11% (7/65) and most were minor wound complications. There were no plantar nerve injuries noted. There were no nail cut outs from the calcaneum. On all markers of hindfoot alignment, cases showed a more physiological degree of hindfoot valgus compared to pre-operative measures. There were significant improvement in both EQ5D and MOXFQ scores (p<0.05). Conclusion: We present the largest series of TTC fusion using a straight intramedullary nail and the first series to analyse hindfoot alignment using weight bearing 3D CT imaging. Our data regarding correction of hindfoot alignment is supported by biomechanical theories of subtalar varus/valgus, being related to rotatory changes at the subtalar joint, questioning the perceived need for a curved nail. This is particularly at the level of the entry point of the nail. The principles of valgus hindfoot nails are based on biomechanical laboratory studies and cadaveric studies, neither of which reflect our findings in clinical practice.

Role of Tendoscopy in Treating Stage II Posterior Tibial Tendon Dysfunction

Background: Stage II tibialis posterior tendon dysfunction (PTTD) resistant to conservative therapies is usually treated with invasive surgery. Posterior tibial tendoscopy is a novel technique being used in the assessment and treatment of posterior tibial pathology. The aims of this study were (1) to clarify the role of posterior tibial tendon tendoscopy in treating stage II PTTD, (2) to arthroscopically classify spring ligament lesions, and (3) to compare the arthroscopic assessment of spring ligament lesions with magnetic resonance imaging (MRI) and ultrasonographic (US) data. Methods: We reviewed prospectively collected data on 16 patients affected by stage II PTTD and treated by tendoscopy. We report the reoperation rate and functional outcomes evaluated by comparing pre- and postoperative visual analogic scale for pain (VAS-pain) and the Short-Form Health Survey (SF-36; with its physical [PCS] and mental [MCS] components). Postoperative satisfaction was assessed using a VAS-satisfaction scale. One patient was lost to follow-up. Spring ligament lesions were arthroscopically classified in 3 stages. Discrepancies between preoperative imaging and intraoperative findings were evaluated. Results: At a mean of 25.6 months’ follow-up, VAS-pain (P < .001), SF-36 PCS (P = .039), and SF-36 MCS (P < .001) significantly improved. The mean VAS-satisfaction score was 75.3/100. Patients were relieved from symptoms in 80% of cases, while 3 patients required further surgery. MRI and US were in agreement with intraoperative data in 92% and 67%, respectively, for the tendon assessment and in 78% and 42%, respectively, for the spring ligament. Conclusions: Tendoscopy may be considered a valid therapeutic tool in the treatment of stage II PTTD resistant to conservative treatment. It provided objective and subjective encouraging results that could allow continued conservative therapy while avoiding more invasive surgery in most cases. MRI and US were proven more useful in detecting PT lesions than spring ligament tears. Further studies on PT could use this tendoscopic classification to standardize its description. Level of Evidence: Level IV, therapeutic study, case series.

Turf toe: A clinical update

Turf toe is a condition that describes injury to the plantar metatarsophalangeal-sesamoid complex of the great toe. It is a relatively rare and debilitating condition, particularly seen in American footballers after the introduction of harder, artificial ‘turf’ surfaces. Turf toe represents a significant injury to the hallux and requires a high index of suspicion. If unrecognized, it can lead to chronic problems including reduced push-off strength, persistent pain, progressive deformity and eventual joint degeneration. Patients with chronic injuries may have worse outcomes, and therefore early, accurate diagnosis and initiation of treatment play a vital role. A multidisciplinary team approach is key for successful return to sport. Cite this article: EFORT Open Rev 2018;3:501-506. DOI: 10.1302/2058-5241.3.180012

Don’t put your foot in it: a case of talonavicular septic arthritis

We present the second documented case of primary septic arthritis of the talonavicular joint. This patient had a number of medical comorbidities, including chronic widespread pain including the ipsilateral limb, which made diagnosis an even greater challenge. Although a clinical diagnosis, joint fluid aspiration remains the gold standard. Prompt surgical drainage with adjuvant antibiotic treatment is recommended, and management requires a multidisciplinary team approach. The aim of treatment is to avoid the sequelae of joint destruction, pain and foot deformity.