Outcome following soft tissue coverage with a medial gastrocnemius flap of an exposed or infected total knee arthroplasty.

BACKGROUND: Soft tissue defects or periprosthetic infections after total knee arthroplasty (TKA) are severe complications that may lead to loss of the arthroplasty or the limb. Reconstructions with medial gastrocnemius flaps (MGF) are occasionally used to provide soft tissue coverage around the knee. AIMS: The study aimed to establish the rate of implant survivorship after MGF reconstruction for soft tissue coverage in the treatment of exposed or infected TKA and to establish functional outcome. METHODS: A retrospective analysis was performed on all patients who received soft tissue coverage with an MGF of an exposed or infected TKA between 2000 and 2017 at the Department of Hand and Plastic Surgery at Umeå University Hospital. The outcomes were implant survivorship and patient-reported outcome measures (PROMs) using the five-level EQ-5D version and The Knee Injury and Osteoarthritis Outcome Score. RESULTS: Forty-seven patients (mean age = 67 years, 30 women) were included. The mean time between flap coverage and follow-up was 6.7 (±3.4) years. Implant survivorship was observed in 28 of 47 (59.6%) patients at follow-up. Flap failure was rare, with only 3 of 47 (6.4%) cases. Of the 20 patients who answered the PROMs, 10 of 20 experienced moderate to severe pain or discomfort. CONCLUSIONS: Due to unfavorable underlying conditions, MGF reconstruction after TKA is often associated with a compromised functional outcome. Because donor site morbidity is limited and flap failure is unusual, the procedure can be considered prophylactically in a small subset of patients with risk factors to prevent soft tissue defects and periprosthetic joint infection.

Muscle changes in patients with diabetes and chronic exertional compartment syndrome before and after treatment with fasciotomy.

INTRODUCTION: Muscle changes in patients with diabetes and lower leg pain due to chronic exertional compartment syndrome (CECS) were investigated before and after fasciotomy. METHODS: The tibialis anterior muscle was analyzed with histochemical and morphological techniques in 7 patients with diabetes and CECS before fasciotomy and in 5 of them 1 year after fasciotomy. Nondiabetic patients with CECS and healthy participants served as references. RESULTS: Before treatment, walking distance until occurrence of pain was limited (<0.2 km). Intramuscular pressure was significantly higher than in reference participants. Muscle analysis showed changes pathognomonic for neuropathy and myopathy and a restricted capillary network, with significantly more severe changes in the muscles of patients with diabetes than in the muscles of nondiabetic patients. Treatment with fasciotomy improved clinical signs, increased walking ability, and reduced muscle abnormalities, but muscle capillarization remained low. DISCUSSION: Patients with diabetes and CECS have distinct pathological changes in affected muscles. Pressure-relieving fasciotomy triggers a regenerative response in the muscle tissue but not in the capillary bed. Muscle Nerve 57: 229-239, 2018.

Muscle oxygenation in Type 1 diabetic and non-diabetic patients with and without chronic compartment syndrome.

BACKGROUND: Type 1 diabetic patients and non-diabetic patients were referred for evaluation for chronic exertional compartment syndrome (CECS) based on clinical examination and complaints of activity-related leg pain in the region of the tibialis anterior muscle. Previous studies using near-infrared spectroscopy (NIRS) showed greater deoxygenation during exercise for CECS patients versus healthy controls; however, this comparison has not been done for diabetic CECS patients. METHODS: We used NIRS to test for differences in oxygenation kinetics for Type 1 diabetic patients diagnosed with (CECS-diabetics, n = 9) versus diabetic patients without (CON-diabetics, n = 10) leg anterior chronic exertional compartment syndrome. Comparisons were also made between non-diabetic CECS patients (n = 11) and healthy controls (CON, n = 10). The experimental protocol consisted of thigh arterial cuff occlusion (AO, 1-minute duration), and treadmill running to reproduce symptoms. NIRS variables generated were resting StO2%, and oxygen recovery following AO. Also, during and following treadmill running the magnitude of deoxygenation and oxygen recovery, respectively, were determined. RESULTS: There was no difference in resting StO2% between CECS-diabetics (78.2±12.6%) vs. CON-diabetics (69.1±20.8%), or between CECS (69.3±16.2) vs. CON (75.9±11.2%). However, oxygen recovery following AO was significantly slower for CECS (1.8±0.8%/sec) vs. CON (3.8±1.7%/sec) (P = 0.002); these data were not different between the diabetic groups. StO2% during exercise was lower (greater deoxygenation) for CECS-diabetics (6.3±8.6%) vs. CON-diabetics (40.4±22.0%), and for CECS (11.3±16.8%) vs. CON (34.1±21.2%) (P<0.05 for both). The rate of oxygen recovery post exercise was faster for CECS-diabetics (3.5±2.6%/sec) vs. CON-diabetics (1.4±0.8%/sec) (P = 0.04), and there was a tendency of difference for CECS (3.1±1.4%/sec) vs. CON (1.9±1.3%/sec) (P = 0.05). CONCLUSION: The greater deoxygenation during treadmill running for the CECS-diabetics group (vs. CON-diabetics) is in line with previous studies (and with the present study) that compared non-diabetic CECS patients with healthy controls. Our findings could suggest that NIRS may be useful as a diagnostic tool for assessing Type 1 diabetic patients suspected of CECS.

Stiffness and thickness of fascia do not explain chronic exertional compartment syndrome.

BACKGROUND: Chronic exertional compartment syndrome is diagnosed based on symptoms and elevated intramuscular pressure and often is treated with fasciotomy. However, what contributes to the increased intramuscular pressure remains unknown. QUESTIONS/PURPOSES: We investigated whether the stiffness or thickness of the muscle fascia could help explain the raised intramuscular pressure and thus the associated chronic compartment syndrome symptoms. PATIENTS AND METHODS: We performed plain radiography, bone scan, and intramuscular pressure measurement to diagnose chronic compartment syndrome and to exclude other disorders. Anterior tibialis muscle fascial biopsy specimens from six healthy individuals, 11 patients with chronic compartment syndrome, and 10 patients with diabetes mellitus and chronic compartment syndrome were obtained. Weight-normalized fascial stiffness was assessed mechanically in a microtensile machine, and fascial thickness was analyzed microscopically. RESULTS: Mean fascial stiffness did not differ between healthy individuals (0.120 N/mg/mm; SD, 0.77 N/mg/mm), patients with chronic compartment syndrome (0.070 N/mg/mm; SD, 0.052 N/mg/mm), and patients with chronic compartment syndrome and diabetes (0.097 N/mg/mm; SD, 0.073 N/mg/mm). Similarly, no differences in fascial thickness were present. There was a negative correlation between fascial stiffness and intramuscular pressure in the patients with chronic compartment syndrome and diabetes. CONCLUSIONS: The lack of difference in fascial thickness and stiffness in patients with chronic compartment syndrome and patients with chronic compartment syndrome and diabetes compared with healthy individuals suggests structural and mechanical properties are unlikely to explain chronic compartment syndrome. To prevent chronic exertional compartment syndrome, it is necessary to address aspects other than the muscle fascia. LEVEL OF EVIDENCE: Level II, prognostic study. See the guidelines online for a complete description of level of evidence.

Intermittent claudication in diabetes mellitus due to chronic exertional compartment syndrome of the leg: an observational study of 17 patients.

BACKGROUND AND PURPOSE: Intermittent claudication in diabetes mellitus is commonly associated with arterial disease but may occur without obvious signs of peripheral circulatory impairment. We investigated whether this could be due to chronic exertional compartment syndrome (CECS). PATIENTS AND METHODS: We report on 17 patients (3 men), mean age 39 (18-72) years, with diabetes mellitus--12 of which were type 1--and leg pain during walking (which was relieved at rest), without clinical signs of peripheral arterial disease. The duration of diabetes was 22 (1-41) years and 12 patients had peripheral neuropathy, retinopathy, or nephropathy. The leg muscles were tender and firm on palpation. Radiography, scintigraphy, and intramuscular pressure measurements were done during exercises to reproduce their symptoms. RESULTS: 16 of the 17 patients were diagnosed as having CECS. The intramuscular pressures in leg compartments were statistically significantly higher in diabetics than in physically active non-diabetics with CECS (p < 0.05). 15 of the 16 diabetics with CECS were treated with fasciotomy. At surgery, the fascia was whitish, thickened, and had a rubber-like consistency. After 1 year, 9 patients rated themselves as excellent or good in 15 of the 18 treated compartments. The walking time until stop due to leg pain increased after surgery from less than 10 min to unlimited time in 8 of 9 patients who were followed up. INTERPRETATION: Intermittent claudication in diabetics may be caused by CECS of the leg. The intramuscular pressures were considerably elevated in diabetics. One pathomechanism may be fascial thickening. The results after fasciotomy are good, and the increased pain-free walking time is especially beneficial for diabetics.

Chronic compartment syndrome also affects nonathletic subjects: a prospective study of 63 cases with exercise-induced lower leg pain.

BACKGROUND: Chronic exertional compartment syndrome is most often reported in young and physically active people. PATIENTS AND METHODS: We studied 73 consecutive patients (mean age 39 (16-77) years, 45 women) with a history of exercise-induced pain and suspicion of chronic exertional compartment syndrome (CECS) of the lower leg--clinically, radiographically and with intramuscular pressure measurements. RESULTS: Intramuscular pressure increased with reproduction of symptoms and fulfilled the criteria for diagnosis of CECS in 36 patients (mean age 36 (16-65) years, 22 women), with engagement of 66 anterior, 2 lateral and 7 posterior muscle compartments in 72 legs. The patients with CECS of the lower leg were divided into 4 etiological groups: 18 with overuse, 10 with earlier trauma, 4 insulin-treated diabetics, and 4 others. Two-thirds of the patients had pain during walking. The outcome after fasciotomy was excellent or good in 41/57 of the legs. INTERPRETATION: CECS of the lower leg probably has a multifactorial etiology and is more common in sedentary individuals than has been recognized previously. Fasciotomy appears to be beneficial in these cases also.