Stephen R. Kearns

The past, present and future in scaffold-based tendon treatments

Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained release of therapeutics/biologics; and the ability to positively interact with the host to promote repair and regeneration. Herein, we critically discuss current therapies and emerging technologies that aim to transform tendon treatments in the years to come.

A pilot evaluation of a neuromuscular electrical stimulation (NMES) based methodology for the prevention of venous stasis during bed rest

Bed rest poses an increased risk factor for a potentially fatal venous thromboembolism (VTE). Lack of activation of the calf muscle pump during this resting period gives rise to venous stasis which may lead to deep vein thrombosis (DVT) development. Our aim was to investigate the effects that 4h of bed rest have on the lower limb hemodynamics of healthy subjects and to what extent electrically elicited contractions of the calf muscles can alleviate these effects. Outcome variables included popliteal vein blood flow and heart rate. Primary results indicated that the resting group experienced a significant decline in popliteal venous blood flow of approximately 47% with approximately 13% decrease in heart rate. The stimulated groups maintained a significantly higher venous blood flow and heart rate. Volume flow in the contralateral limb remained constant throughout the study and was comparable to that of the stimulated limbs recovery flow. The results suggest that even short periods of bed rest can significantly reduce lower limb blood flow which could have implications for DVT development. Electrically elicited calf muscle contractions significantly improve lower limb blood flow and can alleviate some debilitating effects of bed rest.

Patient tolerance of neuromuscular electrical stimulation (NMES) in the presence of orthopaedic implants

Neuromuscular electrical stimulation (NMES) may help reduce the incidence of deep vein thrombosis (DVT) in the postoperative total hip and knee arthroplasty patient. However, discomfort associated with stimulus may reduce patient acceptance of NMES as therapy. The aim of this study was to determine if patient comfort and tolerance of NMES was affected by applying stimulation in proximity to an orthopaedic implant. There was a concern that this may cause a concentration of current around the metal which could result in hypersensitivity of NMES and reduce its effectiveness. Twenty patients took part in this study, 10 total hip and 10 total knee arthroplasty patients. Each patient was at least 3 weeks post surgery. NMES was applied to the calf muscles of each leg using skin surface electrodes. Four excitatory levels were recorded, which were: sensory threshold, motor threshold, pain threshold and pain tolerance. Following this, patients underwent a 5 min stimulation session and indicated their overall comfort level on a visual analogue scale. Measurements of peak venous velocity, mean velocity and volume flow were recorded by duplex scanning from the popliteal vein at rest and in response to NMES elicited contractions during this session. Finally, patients completed a short verbal interview detailing their experience with the NMES treatment. The blood flow results showed increases in peak venous velocities, mean velocities and volume flow produced by NMES of 200%, 60% and 60% respectively when compared to resting blood flow. Comfort assessment indicated that the presence of a metallic implant did not give rise to hypersensitivity due to NMES. Patients found the application of calf muscle NMES comfortable and acceptable as a treatment. We conclude that the use of NMES on postoperative orthopaedic patients can be safely administered as a DVT prevention method.

Volar plate versus k-wire fixation of distal radius fractures

The optimal management of distal radius fractures remains controversial. The aim of this study was to compare the radiographic and functional outcomes of 318 patients who underwent k-wire fixation or volar plating for fractures of the distal radius. Patients were aged between 20 and 65 years and followed for a mean of 32 months. The mean values for volar tilt, radial inclination, radial length and ulnar variance were all significantly better in the volar plate group. Malunion occurred in 13.2% of patients undergoing k-wiring and 4% of patients treated with a volar plate (p<0.007). Higher values for radial inclination, radial length and volar tilt correlated with better functional outcome as measured by disabilities of the arm shoulder and hand (DASH) and patient rated wrist evaluation (PRWE) scores. Lower values for ulnar variance correlated with better functional outcome. Although volar plate treatment resulted in a superior radiological outcome, there was no evidence that this translated into a superior functional outcome (DASH 13.12 vs. 11.25, p=0.28) (PRWE 17.56 vs. 16.31, p=0.69). The k-wiring procedure remains a suitable inexpensive option for simple fractures. Volar plating should be reserved for complex fractures that cannot be reduced by closed means.

Use of a Geometric Formula to Improve the Radiographic Correction Achieved by the Scarf Osteotomy

Background: Many procedures for hallux valgus treatment have high recurrence rates, often related to operative considerations such as accuracy of deformity correction, soft tissue balancing and sesamoid alignment. Inadequate distal metatarsal-articular angle (DMAA) correction is common with uni- and bi-planar osteotomies which principally address the inter-metatarsal angle (IMA). The scarf osteotomy is a tri-planar osteotomy which corrects the DMAA and IMA, thereby achieving a more anatomical correction and potentially reducing the recurrence rate. Our hypothesis was that by controlling the length and relative proximal and distal translations of the scarf with a geometric formula, more accurate correction of the IMA and DMAA is possible. Methods: A formula was generated to determine the specific adjustments required to correct the deformity. A prospective trial was performed to assess the accuracy of this formula. Thirty-four adult patients were enrolled in the study. Seventeen patients underwent a standard scarf procedure; 17 were operated on using the corrections prescribed by the formula. Results: Hallux valgus angle (HVA), IMA and DMAA corrections improved with the formula (p = 0.036, p = 0.049, and p = 0.006, respectively). Patient and procedure selection has changed in our unit as a result of this study, which identified some preoperative deformities as beyond the capabilities of the scarf procedure. Conclusion: The formula allows precise, reproducible, anatomical correction of IMA and DMAA deformities. The degree of correction attainable with the scarf is dependent on the first metatarsal width and the preoperative deformities. The formula highlighted the limitations of the scarf, thereby aiding in appropriate patient and procedure selection. Level of Evidence: II, Prospective Comparative Series

Prospective Evaluation of Intra-Articular Sodium Hyaluronate Injection in the Ankle

Abstract Viscosupplementation by injection of hyaluronic acid into the ankle can be used to provide pain relief and to delay the need for surgery in patients with osteoarthritis of the ankle. In the present investigation, we prospectively evaluated 50 consecutive patients (25 males and 25 females) undergoing a 3‐injection protocol of sodium hyaluronate viscosupplementation in the ankle from January 2014 to January 2015. The Foot and Ankle Outcomes Score was used to compare the patients’ pre‐ and post‐treatment opinions about their ankle problems. The mean pretreatment Foot and Ankle Outcomes Score was 48 ± 6.3 (range 25 to 84) and the 6‐month post‐treatment score was 78 ± 5.8 (range 48 to 100). This difference was statistically significant (p = .003). From our findings in the present prospective cohort study, we have concluded that intra‐articular injection of sodium hyaluronate viscosupplementation is a useful conservative therapy for osteoarthritis of the ankle. &NA; Level of Clinical Evidence: 3

Ligamentous advancement for the treatment of subacute syndesmotic injuries. Report of a new technique in 5 cases

BACKGROUND Integrity and optimum functioning of the syndesmotic ligament complex is of paramount importance for stability of the ankle joint during various ankle movements. Persistent widening and chronic isolated instability of the distal tibio-fibular syndesmosis leads to poor functional outcome and the development of osteoarthritis. In subacute total ruptures the focus of treatment is to restore the normal anatomy by repair of the ruptured ligament and to protect the reconstruction for a period of time. Various techniques have been previously reported with good results but associated with donor site morbidity and multiple incisions. METHOD Ligamentous advancement allows repair of the syndesmosis when the AITFL is dysfunctional but intact. The lax AITFL was mobilised with periosteum from the tibia leaving the fibular side intact. The Syndesmosis was cleared, reduced with a clamp, and held with two syndesmotic screws inserted transversely between the distal fibular and tibial shafts. The tibial surface was roughened to receive the new attachment of AITFL. The sleeve of tissue was then secured to the roughened tibial surface under tension using suture anchors with the ankle in neutral position. The repair was protected with a two hole plate and screws. RESULTS The functional outcome scores showed excellent outcome at the end of 6 months. CONCLUSION Ligamentous advancement technique obviates the need of any bony procedure and does not involve the use of any material which will lead to any sort of foreign body reaction or donor site morbidity while providing anatomical reconstruction of the syndesmosis with excellent functional outcome.

A hemodynamic study of popliteal vein blood flow: The effect of bed rest and electrically elicited calf muscle contractions

Venous stasis, due to lack of activation of the calf muscle pump of postoperative patients, can result in the development of a thrombus which, in turn, can lead to a potentially fatal pulmonary embolism. The presented study investigates the effects that four hours of bed rest has on the lower limb hemodynamics of healthy subjects and, to what extent electrically elicited contractions of the calf muscles can alleviate these effects. Results indicated that the non-stimulated group experienced a decline in popliteal venous blood flow of approximately 45 % and a 10 % decrease in heart rate. The stimulated group maintained a higher venous blood flow and heart rate. The results suggest that even short periods of bed rest can significantly reduce lower limb blood flow which could have implications for DVT development in post-operative patients. Electrically elicited calf muscle contractions significantly improves lower limb blood flow and can alleviate the debilitating effects of bed rest.

Analysis of risk factors for failure of arthroscopic ankle fusion in a series of 52 ankles

BACKGROUND The purpose of this retrospective study is to analyze the effect of different variables on union rate and functional outcome in patients who underwent arthroscopic ankle fusion for end-stage arthritis of ankle. METHODS Clinical records and radiographs were reviewed to evaluate the variables that could predispose patients to non-union and poor functional outcome. Union and functional outcomes were correlated with different variables. RESULTS Fifty patients had arthroscopic ankle fusion on 52 ankles. The mean age at the time of surgery was 59.4 (27-80) years and mean length of follow up was 32.1 (8-78) months. Forty-eight out of 52 ankles (92.3%) achieved radiographic and clinical union. The average time to fusion was 12.2 (8-28) weeks. The time taken for union was significantly higher in smokers as compared to non-smokers (p<0.001). All the patients in this series who had non-union shared one common factor - neuromuscular imbalance. Age, gender, smoking, diabetes, steroid, bisphosphonates, neuropathy, frontal and sagittal plane alignment and tibial-axis-to-talus (T:T) ratio did not significantly affect the union rate and functional outcome. CONCLUSION Smokers should refrain from smoking before surgery and patients with neuromuscular problems may require more rigid fixation and a longer period of immobilization to achieve more consistent union rates.

Flexor digitorum accessorius causing tarsal tunnel syndrome in a paediatric patient: A case report and review of the literature

The flexor digitorium accessorius muscle is an unusual anatomical variant found in the posteromedial aspect of the hindfoot and ankle. As previously described, its location predisposes patients to developing tarsal tunnel syndrome. This case illustrates the diagnosis, treatment and resolution of tarsal tunnel syndrome in a paediatric patient, secondary to the presence of flexor digitorium accessorius muscle.