Treatment of Extensor Lag Using the Flexor Digitorum Superficialis after Crushing-Penetrating Injury to the Metacarpophalangeal Joint

We previously reported the beneficial effects of tendon transfer to eliminate extension lag of the interphalangeal joints, using the extensor carpi radialis longus prolonged by palmaris longus tendon grafts after crushing-penetrating injuries around the metacarpophalangeal (MP) joint of the middle finger. We used the flexor digitorum superficialis (FDS) as the alternative donor muscle and treated two cases of severe crushing injuries to MP joint, and then obtained good outcomes.

Reach out and grasp the opportunity: reconstructive hand surgery in tetraplegia

Reconstructive upper extremity surgeries in tetraplegia are technically challenging because of the many complicated real-time decisions that need to be made, e.g. extent of release of donor muscle-tendon complex, routing of donor muscles, tissue preparation and optimization, tensioning of muscle-tendon units, balancing joints and suturing tendon-to-tendon attachments. Nerve transfer surgeries can add functionality but also make the reconstruction planning more complex. In this overview, we present some of the fundamental muscle-tendon-joint mechanics studies that allow for single-stage surgical reconstruction of hand function as well as early postoperative activity-based training in patients with cervical spinal cord injuries. We foresee an increased need for studies addressing combined nerve and tendon transfer reconstructions in parallel with patient-perceived outcome investigations. These should be combined with implementation of assistive technology such as functional electrical stimulation for diagnostic, prognostic and training purposes.

Brachialis muscle transfer for reconstructing digital flexion after brachial plexus injury or forearm injury

Restoration of digital flexion after brachial plexus injury or forearm injury has been a great challenge for hand surgeons. Nerve transfer and forearm donor muscle transfer surgeries are not always feasible. The present study aimed at evaluating the effectiveness of restoring digital flexion by brachialis muscle transfer. Ten lower brachial plexus- or forearm-injured patients were enrolled. After at least 12 months following surgery, the middle-finger-to-palm distance was less than 2.5 cm in six patients. In the other four patients with less satisfactory results, secondary tenolysis surgery was performed and the middle-finger-to-palm distances were reduced to 2.0–4.0 cm. The average grasp strength was 20 ± 4 kg. Elbow flexion was not adversely affected. In conclusion, brachialis muscle transfer is an effective method for reconstructing digital flexion, not only in lower brachial plexus injury, but also in forearm injury patients. Level of evidence: IV

HAMSTRING MORPHOLOGY AND STRENGTH REMAIN ALTERED 2 YEARS FOLLOWING A HAMSTRING GRAFT IN ACL RECONSTRUCTION

Background: The hamstring graft used in anterior cruciate ligament (ACL) reconstruction has been shown to lead to changes to the semitendinosus and gracilis musculature. This study further evaluated the effect of the surgery on hamstring muscle morphology and knee muscle strength at 2 years post-surgery. Hypotheses: (1) Loss of donor muscle size would significantly correlate with knee muscle strength deficits (2) Loss of donor muscle size would be greater for muscles that do not experience tendon regeneration, and (3) Morphological adaptations would also be evident in non-donor knee muscles. Study Design: Cross sectional evaluation. Methods: 20 participants (14 male, 6 female, 29 ± 7 years, 82 ± 15 kg) that had undergone a hamstring graft in ACL reconstruction at least two years previously, underwent bilateral MRI and subsequent strength testing. Muscle and tendon volumes, peak CSA’s and lengths were determined for 12 muscles and 6 functional muscle groups of the surgical and contralateral limbs. Peak isokinetic concentric strength was measured in knee flexion/extension and internal/external tibial rotation. Results: Only 50% of the patients regenerated both the semitendinosus and gracilis tendons. The regenerated tendons were longer with larger volume and CSA compared to the contralateral side. Deficits in semitendinosus and gracilis muscle size were greater for tendons that did not regenerate. In addition, combined hamstrings (semitendinosus, semimembranosus, biceps femoris) and combined medial knee muscles (semitendinosus, semimembranosus, gracilis, vastus medialis, medial gastrocnemius, sartorius) on the surgical side were reduced in volume by 12% and 10% respectively. A 7% larger volume was observed in the surgical leg for the biceps femoris and corresponded with a lower internal/external tibial rotation strength ratio. The difference in volume, peak CSA and length of the semitendinosus and gracilis correlated significantly with the deficit in knee flexion strength with Pearson correlations of 0.51, 0.57 and 0.61 respectively. Conclusion: The muscle-tendon properties of the semitendinosus and gracilis are substantially altered following harvesting, and these alterations may contribute to knee flexor weakness in the surgical limb. These deficits are more pronounced in tendons that do not regenerate and are only partially offset by compensatory hypertrophy of other hamstring muscles. Clinical Relevance: Surgeons should consider muscle retraction of the hamstring following tendon harvest in their choice of graft option for ACL reconstruction.

Management of Total Paralysis of the Brachial Plexus by the Double Free-muscle Transfer Technique

The double free-muscle transfer technique achieved a dramatic revolution in the treatment of total paralysis of the brachial plexus by providing universal prehensile function, although several requirements such as successful free-muscle transfers, stability of the proximal joints and prolonged postoperative rehabilitation are necessary for the success of this procedure. To obtain the best outcome of double free-muscle transfer, it is imperative to understand the key factors, viz. selection of the donor muscle, meticulous microsurgical technique, importance of proximal joint stability, selection of the kind of grip and postoperative rehabilitation. Double free-muscle transfer is not a simple microsurgical muscle transfer for finger movement, but a universal reconstructive procedure for total paralysis of the upper limb.