Muscle Belly Repair: Biomechanical Assessment of the Anchor Suture and the Modified Kessler Techniques.

Background: Treatment of muscle belly lacerations remains a problem for surgeons. Inadequate repair of lacerations can cause functional disability. To date, there is no consensus on the method of repair for these injuries. We have previously described a technique of repairing mid-substance muscle belly lacerations. The aim of this study was to determine the ultimate strength of an intact muscle belly and to compare the anchor suture (AS) technique with the modified Kessler (MK) technique. Methods: Fifteen fresh frozen hind-legs from adolescent pigs were divided into three groups and used for the testing. Each group consisted of five specimens. Group one was the intact control group, group two was repaired with the MK technique and group three was repaired with the AS technique. Following repair, the muscles were secured in a custom-made fixation apparatus and underwent linear tensioning at a rate of 25 mm/min, generating a load-displacement curve for each specimen. The data regarding ultimate strength, modes of failure and number of intact suture/anchor constructs (for groups 2 and 3) was calculated. Results: The ultimate strength of the intact muscle group of was found to be 608.1 ± 107.9  N. This was significantly (p < 0.05) higher than the pull-out strength of the MK and AS groups. The pull-out strength of the AS group was 143.1 ± 36.7 N, nearly twice that of the MK group 69.8 ± 16.4 N (p = 0.11). Suture pull-out was the most common mode of failure. Conclusions: The AS technique was found to have both higher strain and nearly twice the ultimate pull-out strength compared to the MK repair group. We suggest the AS technique as a viable technique for mid-substance muscle belly repairs.

Simplified and strong: abductor pollicus longus suspension arthroplasty with biotenodesis screw fixation in the base of the index metacarpal.

Surgical treatment of thumb basal joint arthritis is aimed at pain relief, restoration of pinch strength, and stability. We describe a variation of the abductor pollicus longus (APL) suspension arthroplasty originally described by Thompson, which maximizes strength of repair and is technically simple to perform. The technique consists of a trapeziectomy followed by resection of a slip of the APL and secure docking of the tendon into the base of the index metacarpal base. Stability is enhanced with a 3.0 mm biotenodesis screw. From March 2009 to September 2011, 50 patients were treated at our institution. Early results showed consistent pain relief, functional improvement, and minimal complications. The data support APL suspension arthroplasty with tenodesis screw fixation as a safe and effective treatment for CMC arthritis.

Superior medial geniculate artery pseudoaneurysm after primary total knee arthroplasty.

Vascular complications after total knee arthroplasty are rare. To date, there are 7 reported cases of pseudoaneurysms affecting the popliteal artery and 6 cases affecting one of the geniculate arteries. We present a case of a geniculate artery pseudoaneurysm that shared symptoms of a deep venous thrombosis on physical examination of a patient who underwent primary total knee arthroplasty. To date, there are no reports in American literature of pseudoaneurysms affecting the superior medial geniculate artery after primary total knee arthroplasty. After a vascular workup including computed tomographic angiography, surgical management included evacuation of the pseudoaneurysm and ligation of the feeding artery. The patient went on to successful recovery.

Anchor suture technique for muscle belly repair.

Upper extremity lacerations occur frequently. Although surgical indications for tendon repair are widely accepted, indications for repairing the midsubstance of muscles are not as clear. As the standard of care for muscle repair is absent, there are a variety of techniques available to the treating surgeon. In this study, we describe a technique used on several patients seen in our orthopedic practice. The use of orthogonally placed anchor sutures allows for more reliable suture passes and purchase in the muscle belly compared with simple end-to-end approximation. Furthermore, our technique does not introduce excessive foreign material as has been suggested by previous techniques.

Survival of porcine mesenchymal stem cells over the alginate recovered cellular method.

Although previous studies have established alginate as a three-dimensional scaffold for chondrogenic differentiation of mesenchymal stem cells (MSCs), little is known about the cytotoxic effects of the polymerizing and chelating reagents used in the alginate recovered cellular method. Swine MSCs (sMSC) were suspended in the polymerizing agent, CaCl(2), and viability was assessed using a trypan blue exclusion assay at intervals over 2 h. MSCs were also suspended in two different chelating agents, 55 mM sodium citrate and 50 mM EDTA, and viability was calculated. Finally, sMSCs and human MSCs were encapsulated and cultured in vitro. The sMSC were collected at day 4 and the cells were recovered by chelation. Encapsulated hMSCs were cultured with TGFß3 and IGF-1 and assayed by qRT-PCR for collagen types I and II and sox9 with encapsulated human dermal fibroblasts and chondrocytes as controls recovered on days 0, 7, and 14. Only 53% of sMSCs were viable after 10 min in CaCl(2), the standard polymerization period, whereas 94% of encapsulated sMSCs in polymerized alginate were alive at 15 days. After 20 min in chelating agents, sodium citrate and EDTA, only 46% and 17% of the cells, were viable, respectively. The alginate recovered sMSCs yielded 12% survival. Human MSCs upregulated cartilage-specific collagen type II over the 14-day culture. Collagen I remained unchanged in the hMSCs. Alginate is a suitable agent for chondrodifferentiation of MSCs and can be dissolved by chelation, but the agents involved in hydrogel polymerization and cell recovery should be altered to improve MSC survival.

Subchondral cysts of the atlantoaxial joint: a risk factor for odontoid fractures in the elderly.

BACKGROUND CONTEXT: Scholars have postulated that cervical degeneration can predispose the upper cervical spine to injury after minor trauma. Subchondral cysts have previously been recognized as potentiators of fracture in the hip and knee but no cases of cervical degenerative cysts contributing to fracture have been reported. PURPOSE: This report documents a case series in which patients sustained significant injury to the upper cervical spine in the setting of subchondral cervical cysts. STUDY DESIGN/SETTING: Case series/academic level I trauma center. METHODS: Between 2004 and 2008, six patients (ages 73-91 years) with cervical pathology were admitted to the trauma service at our Level I trauma center. The most common mechanism of injury was a low velocity fall, which occurred in 5 out of 6 patients. All patients suffered an odontoid fracture. In all cases, there was radiographic evidence of cyst formation, and computed tomographic imaging demonstrated fracture communication with the subchondral cyst. RESULTS: Of the six cases, four were treated definitively with immobilization in a cervical orthosis and two required surgery. One patient was treated with an occipital-cervical fusion, whereas the other underwent Brooks wiring. All patients ultimately went on to heal their fractures. CONCLUSIONS: Degenerative changes in the cervical spine have previously been recognized to potentiate injury. This report raises the question of whether degenerative processes at the C1-C2 articulation predispose elderly patients to injury at this level. The presence of cystic degeneration at the atlantoaxial joint should be recognized as a potential risk factor for cervical injury after relatively minor trauma.

Multidirectional instability of the shoulder in elite female gymnasts.

Multidirectional instability (MDI) of the shoulder is symptomatic laxity in 2 or more directions, 1 of which is inferior. MDI is well described in overhead athletes (eg, baseball players, tennis players, swimmers) but not in gymnasts. We conducted this study to estimate the incidence of any type of shoulder pathology in elite gymnasts, to estimate MDI incidence in this population, and to determine which if any circumstances place these gymnasts at higher risk for developing MDI. An 18-question multiple-choice questionnaire was administered to 70 female US collegiate gymnastics teams. Potential risk factors were cross-matched against those gymnasts with traumatic shoulder injuries and again against those gymnasts who met MDI study inclusion criteria. Of the 1115 questionnaires distributed, 457 (34 teams) were returned. Twenty-two percent of gymnasts suffered from a traumatic shoulder injury, and 11% met study inclusion criteria. There was a statistically significant (P =.02) relationship between generalized ligamentous laxity and traumatic shoulder instability but not MDI. Incidence of atraumatic or traumatic shoulder injuries in gymnasts is higher than previously recognized. Although this study did not reveal any potential risk factors, it does provide several avenues for more specific research.