Anatomic study of the flexor carpi ulnaris muscle and its application to soft tissue coverage of the elbow with clinical correlation

Advances in Soft Tissue Injuries Associated with Open Fractures

Management of soft tissue injury is a key component in the overall treatment of upper extremity fractures. Hand surgeons must rely on their armamentarium for treating soft tissue deficits for functional outcomes. Understanding the role of fracture fixation and wound adjuncts, including negative pressure wound therapy and dermal regenerative templates, is the keys to success. In addition, detailed knowledge of local and free tissue options is essential for hand reconstruction.

A novel method intersecting three-dimensional motion capture and medial elbow strength dynamometry to assess elbow injury risk in baseball pitchers

In baseball pitching, resultant elbow varus torque reaches the peak value of 50-120 N m, exceeding the joint failure limit that risks damage to the ulnar collateral ligament (UCL). In-vivo methodology is lacking to assess whether pitchers have sufficient muscular strength to shield UCL and how strongly the elbow musculature must contract to minimize valgus loading on UCL. This study introduces a method to assess relative percentages of muscular varus strength required to unload the UCL. The maximum voluntary isometric varus strength (MVIVS) produced by the medial elbow musculature and the maximum resultant varus torques at elbow in pitching fastballs and other types were measured for two professional pitchers. Simulation was conducted to determine the relative percentages of MVIVS required to unload the UCL to varying degrees and the impact of athletes' previous UCL reconstruction on the relative percentages was examined. The maximum resultant varus torque in pitching was found to range 72-97%MVIVS depending on the type of pitch. The elbow musculature had to produce 21-49%MVIVS to avoid acute failure of intact UCL whereas the corresponding requirements were 39-63%MVIVS for UCL reconstructed joint. The method offers new insight into baseball pitcher's training/rehabilitation and physical assessment to reduce the risk of UCL injury.

Flap survival and functional outcomes in elbow soft tissue reconstruction: A 25-year systematic review

INTRODUCTION

Different elbow flap reconstructions have been described in the literature. We aim to define the optimal flap technique based on defect size and etiology.

METHODS

A systematic review was undertaken using the terms "(Elbow reconstruction) AND ((Soft tissue) OR (flap))". Flaps were grouped under fasciocutaneous (FCF), muscular (MF), distant pedicled (DPF), and free flaps (FF). The primary outcome was flap survival. The secondary outcomes were postoperative complications and range of motion (pROM).

RESULTS

Twenty articles with 224 patients were included. Defect sizes were small (<10 cm²) (18%), medium (10-30 cm²) (23%), large (30-100 cm²) (43%), and massive (>100 cm²) (16%). Etiologies included trauma (26%), burn contractures (26%), infection (26%), hardware coverage (16%), and others (6%). FCF (54%) was the preferred flap followed by MF (28%), DPF (13%), and FF (5%). The rate of flap necrosis was 4% and that of other complications was 10%. The postoperative range of motion (pROM) (reported in 154 patients) was >100°, 50-100°, and <50° in 82%, 17%, and 1% of the cases, respectively. Small defects were most commonly reconstructed with MFs (83%), medium defects were reconstructed with MFs (52%) or FCFs (46%), and large defects were reconstructed with FCFs (91%). Massive defects predominantly required DPFs (60%) and FFs (26%). FCFs were the most common reconstruction method for burn contractures (84%), infections (55%), and traumatic defects (51%). Hardware coverage was predominantly performed using MFs (86%). No difference in complications and pROM was found between flap techniques.

CONCLUSION

Elbow flap reconstruction can be performed using different techniques. FCFs are the most commonly used reconstruction method. MFs are useful for smaller defects and hardware coverage. DPFs and FFs are needed for massive injuries.

Vascularized Olecranon Bone Graft: An Anatomical Study and Novel Technique

PURPOSE

Autologous bone grafting is commonly used in reconstructive hand surgery. Various sources of nonvascularized autologous bone grafts have been described in the literature. However, in some situations, a vascularized bone graft may be needed. Popular vascularized bone grafts are taken from the distal radius, iliac crest, and medial femoral condyle. The purpose of this study was to examine the feasibility of harvesting a free vascularized bone flap from the proximal ulna.

METHODS

Latex was injected via the brachial artery to facilitate visualization of perforators in 10 cadaveric specimens. Dissections were performed of the olecranon; all periosteal perforators were noted, and their lengths and diameters recorded. Corticocancellous bone flaps with their supplying pedicles were harvested. Three additional fresh specimens were injected with india ink via the pedicles to demonstrate perfusion of the harvested bone flap.

RESULTS

Consistent vascular anatomy supplied the olecranon. A perforator from the posterior ulnar recurrent artery supplied the proximal ulna and olecranon, from which a vascularized bone flap can be harvested. Branches to the flexor carpi ulnaris muscle may allow chimeric flaps to be harvested. Average pedicle length was 5.8 cm and average pedicle diameter was 2.4 mm. India ink injection of the pedicles showed perfusion of the periosteum as well as intraosseous cancellous bone.

CONCLUSIONS

A vascularized olecranon free flap can be harvested based on the posterior ulnar recurrent artery. Vascular anatomy is consistent and flap harvest is simple and straightforward in all cadaveric specimens.

CLINICAL RELEVANCE

A vascularized olecranon free flap represents a potential new surgical option when vascular bone flap reconstruction is considered.

Brachioradialis muscle flap for posterior elbow defects: a simple and effective solution for the upper limb surgeon

BACKGROUND

Trauma, infection, and posterior surgical approach are the most frequent causes of soft tissue defects of posterior elbow. The brachioradialis (BR) muscle flap is a rotational muscular pedicled flap, and the dominant vascular pedicle arises from the radial recurrent artery in the proximal portion of the muscle. The aim of the study was to present the BR muscle flap as a simple, safe, and effective solution for the treatment of soft tissue defects of the posterior elbow.

METHODS

Five patients (3 males; mean age, 61.4 years; range, 40-73 years) with soft tissue defects of the posterior elbow underwent surgical treatment with the BR muscle flap. The causes of the defects were total elbow arthroplasty and postsurgical infection (n = 2), 1 patient with elbow arthrodesis due to neuropathic arthropathy, and postsurgical infection after open reduction and internal fixation of olecranon fractures (n = 2). All patients had a BR muscle flap and skin grafting. Orthopedic hardware was removed in 3 cases.

RESULTS

At the mean follow-up of 45 months (range, 26-61 months), all patients had viable and functional soft tissue coverage. All patients were free of infection, whereas 1 patient had a posterior elbow discomfort in daily activities. None of the patients reported wrist problems.

CONCLUSIONS

The BR muscle flap is a reliable solution, easy to harvest without requiring microsurgical expertise for small-size posterior elbow defects. It is a 1-stage procedure with no morbidity to the harvest site that provides stable and adequate coverage even in cases with postoperative infection.

Distally Based Pedicled Flexor Carpi Ulnaris Muscle Flap: An Anatomical Study and Clinical Application

BACKGROUND

Proximally based, pedicled flexor carpi ulnaris (FCU) muscle flap has been described previously for soft tissue coverage of the proximal forearm and elbow. No studies have been done on the distal muscular perforators and its use as a distally based flap.

METHODS

Ten fresh-frozen cadaveric dissections were done. Specimens were injected with latex to facilitate identification of the perforators. Distal muscular perforators were dissected and distances of the pedicles from the distal wrist crease and ulnar styloid were measured and recorded. A clinical case is also presented where a distally based FCU muscle flap was used for coverage in a patient with median nerve neuroma.

RESULTS

A distal muscular perforator and a second more proximal perforator were identified in all specimens. The average distance from the most distal muscular perforator to the ulnar styloid was 3.0 cm. The average distance to the wrist crease was 4.6 cm. The more proximal perforators had an average distance to the ulnar styloid and wrist crease of 7.3 cm and 8.8 cm, respectively. At 7 months post-op, the patient who underwent median nerve neurolysis and coverage with pedicled FCU flap had much improved sensation, with complete resolution of pain and tingling, and without any functional deficits.

CONCLUSIONS

The use of a distally based FCU muscle flap is a good option for soft tissue coverage of the distal forearm, wrist, and hand. The distal muscular perforators from the ulnar artery exhibit a relatively consistent anatomy.

A new local muscle flap for elbow coverage-the medial triceps brachii flap: anatomy, surgical technique, and preliminary outcomes

BACKGROUND

The medial triceps brachii is vascularized by the middle collateral artery and the arterial circle of the elbow. This vascularization allows a distal pedicled use to cover soft tissue defects of the elbow. We report our experience using this flap to cover traumatic and postsurgical wounds.

METHODS

Patients who underwent a pedicled medial triceps brachii flap procedure between 2008 and 2015 were included. Data concerning characteristics of the patients, wound size, surgical technique, and complications were retrospectively reviewed. An independent observer examined patients and assessed outcome of the coverage procedure: wound healing, scar length, range of elbow motion, and patient satisfaction.

RESULTS

Eight patients were included (70.6 ± 17.7 years old at the time of surgery). All patients had serious comorbidities and risk factors of poor wound healing. Defects were due to postoperative healing complications (5 patients), skin necrosis secondary to an underlying olecranon fracture (1 patient), and direct open fractures (2 patients). Soft tissue defects had a median surface of 17 (14-22) cm². The olecranon was exposed in 7 cases and the medial humeral epicondyle in 1 case. Mean procedure duration was 83 ± 14 minutes. There was no intraoperative or postoperative complication. All patients healed properly at 3 weeks of follow-up. No wound recurrence or surgery-related complication was reported after a median follow-up of 40.5 (21.5-69.5) months.

CONCLUSION

Favorable outcomes in all of our 8 patients make this flap an interesting option to cover small to medium-sized defects of the posterior aspect of the elbow.

Bipedicle Flaps for Posterior Elbow Reconstruction

Chronic posterior elbow soft tissue defects often require soft tissue reconstruction because of exposure of the underlying triceps tendon and proximal ulna. Current options for soft tissue coverage require sacrifice of a local muscle or microsurgery. The purpose of this study is to evaluate patient and surgical outcomes after reconstruction of small-sized to medium-sized (<50 cm) posterior elbow defects with bipedicle advancement flaps. A retrospective chart review was performed for 3 patients who underwent posterior elbow reconstruction with bipedicle flaps. The etiology of the soft tissue elbow defect was chronic infected olecranon bursitis (n=2) and exposed olecranon plate after open fracture (n=1). Patient comorbidities included: diabetes, CREST (Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, Telangiectasia) syndrome, and rheumatoid arthritis. The mean patient age at time of reconstruction was 44 years (39 to 51 y), and the mean area of soft tissue defect was 39.3 cm (24 to 54 cm) after debridement of involved tissue. All patients had positive intraoperative cultures and were treated with culture-directed long-term intravenous antibiotics. There were no surgical complications or flap loss. All patients had reepithelialization of the donor site by postoperative week 8 and stable soft tissue coverage of the elbow after surgery at final follow-up with full preoperative elbow range of motion. This technique offers a simple, reliable solution for soft tissue coverage of the posterior elbow using excess local tissue for primary closure of posterior elbow wounds with minimal donor-site morbidity.

Clinical Outcomes of the Flexor Carpi Ulnaris Turnover Flap for Posterior Elbow Soft Tissue Defects

PURPOSE

To report the clinical outcomes from 2 academic centers of the flexor carpi ulnaris (FCU) flap for coverage of posterior elbow soft tissue defects.

METHODS

We retrospectively reviewed 17 patients who underwent an FCU flap for posterior elbow wound reconstruction over an 8-year period at 2 academic centers. Outcome measures included visual analog score for pain; Disabilities of the Arm, Shoulder, and Hand score; Mayo Elbow Performance score; range of motion; wound healing; grip strength; and isokinetic dynamometry for wrist flexion. Wilcoxon signed-rank test was used to make side-to-side comparisons between the operative and nonsurgical extremities, and nonparametric statistical methods were used to analyze results.

RESULTS

All wounds healed successfully without need for revision surgery. Average visual analog, Disabilities of the Arm, Shoulder, and Hand, and Mayo Elbow Performance scores in the operative elbow were 1.8, 34, and 86, respectively. Average elbow arc of motion was 11° to 140° with 70° forearm pronation and 73° forearm supination. Compared with the nonsurgical side, grip strength on the operated side was 97% and wrist flexion peak torque was 89%. The operative limb had an average wrist flexion fatigue of 7%, compared with 22% for the nonsurgical arm.

CONCLUSIONS

Patients receiving an FCU flap had reliable healing, minimal pain, good functional outcomes, and no meaningful deficits in grip strength or wrist flexion strength.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Soft-Tissue Coverage for Elbow Trauma

The elbow is particularly prone to trauma, and soft-tissue reconstruction can be challenging given the inherent motion, pressure, and lack of local tissue laxity. Small wounds and those without exposure of vital structures may be amenable to primary repair. Large wounds and those requiring more substantial structural or anatomic repair may require local, regional or free flap-based reconstruction. A comprehensive review of soft-tissue reconstruction of the elbow is provided to offer surgeons alternative options in complicated upper extremity wounds.