Outcome of medial hamstring lengthening in children with spastic paresis: A biomechanical and morphological observational study

Abstract

To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections have been reported. How these side effects relate to semitendinosus morphology is unknown. This study assessed the effects of bilateral medial hamstring lengthening as part of single-event multilevel surgery (SEMLS) on (1) knee joint mechanics (2) semitendinosus muscle morphology and (3) gait kinematics. All variables were assessed for the right side only. Six children with spastic paresis selected for surgery to counteract limited knee range of motion were measured before and about a year after surgery. After surgery, in most subjects popliteal angle decreased and knee moment-angle curves were shifted towards a more extended knee joint, semitendinosus muscle belly length was approximately 30% decreased, while at all assessed knee angles tendon length was increased by about 80%. In the majority of children muscle volume of the semitendinosus muscle decreased substantially suggesting a reduction of physiological cross-sectional area. Gait kinematics showed more knee extension during stance (mean change ± standard deviation: 34±13°), but also increased pelvic anterior tilt (mean change ± standard deviation: 23±5°). In most subjects, surgical lengthening of semitendinosus tendon contributed to more extended knee joint angle during static measurements as well as during gait, whereas extensibility of semitendinosus muscle belly was decreased. Post-surgical treatment to maintain muscle belly length and physiological cross-sectional area may improve treatment outcome of medial hamstring lengthening.

Interventions and lower‐limb macroscopic muscle morphology in children with spastic cerebral palsy: a scoping review

“…The quality of the three studies that included soft tissue/orthopaedic surgery ranged from fair 38 to poor 39,40 . The effect of surgical elongation on macroscopic muscle–tendon morphology was assessed for the medial gastrocnemius 39,40 and semitendinosus muscles 38 . Gastrocnemius recession was performed by transverse incision of the gastrocnemius tendon and aponeurosis of the soleus muscle distal to the belly of the medial gastrocnemius muscle 40 or by using the Vulpius technique 39 .…”

Orthopedic treatment of the lower limbs in spastic paralysis

“…Orthopedic surgery can roughly be divided into tendon lengthening, tendon transfer, osteotomy, and arthrodesis. The indications include fixed contracture, joint deformity, joint dislocation, and subluxation that affect function or cause pain [18][19][20][21][22]. Furthermore, the purpose of surgery is to improve motor function, prevent deformity, relieve pain, and modify the appearance of patients [23,24].…”

“…Additionally, weakness of quadriceps and triceps surae muscles can lead to excessive flexion of the knee. Flexion contracture of the knee and crouch gait can be satisfactorily improved by distal hamstring elongation [18], which is a simple surgical procedure involving the release of the semitendinosus, semimembranosus, gracilis, and biceps femoris. As the development of severe contracture deformity (fixed knee flexion deformity angle < 40°) or bony deformity, patients could benefit from multilevel surgery (distal femoral extension osteotomy combined with soft tissue surgery) [142].…”

Resistance Training Combined With Stretching Increases Tendon Stiffness and Is More Effective Than Stretching Alone in Children With Cerebral Palsy: A Randomized Controlled Trial

“…However, adverse effects of muscle lengthening surgery have also been reported. Medial hamstring lengthening in children with CP led to a shorter and smaller muscle belly (4), there is a risk of overcorrection (5), and the timing of surgery is essential for its success (6). Therefore, conservative approaches are preferred as a first treatment option.…”