Quantification of humeral head deformity following neonatal brachial plexus palsy.

BACKGROUND: Neonatal brachial plexus palsy frequently leads to glenohumeral dysplasia if neurological recovery is incomplete. Although glenoid retroversion and glenohumeral subluxation have been well characterized, humeral head deformity has not previously been quantified. Nonetheless, humeral head flattening is described as a contraindication to joint contracture release and external rotation tendon transfers. This study describes a novel technique for objectively quantifying humeral head deformity with use of magnetic resonance (MR) imaging and correlates the humeral head deformity with clinical and radiographic outcomes following joint rebalancing surgery. METHODS: Magnetic resonance images of thirty-two children (age, 0.7 to 11.5 years) with neonatal brachial plexus palsy were retrospectively reviewed. Passive shoulder external rotation and Mallet scores were reviewed before joint rebalancing surgery and at a minimum clinical follow-up interval of two years. The humeral head skewness ratio on preoperative and postoperative axial MR images was defined as the ratio of anterior to posterior humeral head area, and this ratio was compared between affected and unaffected shoulders and with the glenoid version angle, posterior subluxation of the humeral head, and clinical parameters before and after surgery with use of paired t tests and Spearman correlation. Intraobserver and interobserver reliability of MR image measurements was determined. RESULTS: Measurements of the skewness ratio on the affected side had moderate to substantial intraobserver reliability (0.53 to 0.72) and substantial interobserver reliability (0.65 to 0.71). Preoperatively, the skewness ratio of the affected humeral head (mean, 0.76; range, 0.54 to 1.03) differed significantly from the ratio in the contralateral shoulder (p<0.05) and was significantly associated with the glenoid version angle (p<0.05) and posterior subluxation of the humeral head (p<0.05). Remodeling of the affected humeral head was observed postoperatively, with a significant improvement in the skewness ratio (p<0.05). However, there were no significant correlations between the preoperative skewness ratio and postoperative clinical outcomes. CONCLUSIONS: Humeral head deformity in neonatal brachial plexus palsy correlated with other measures of glenohumeral dysplasia and could be reliably and objectively quantified on MR imaging with use of the skewness ratio. The humeral head deformity can remodel following joint rebalancing surgery, and such a deformity alone does not preclude a successful outcome after surgical attempts to restore glenohumeral congruity.

Humeral head resurfacing for glenohumeral arthritis associated with dysplasia.

Humeral head resurfacing is indicated for the treatment of glenohumeral arthrosis in a variety of well-described situations, including humeral shaft abnormalities and obstructing hardware. This report of 2 cases emphasizes the benefit of this stemless device in situations in which dislocation of the humeral head and access to the humeral canal is not possible. In these 2 patients with developmental dysplasia and secondary glenohumeral arthrosis, humeral head resurfacing arthroplasty resulted in successful improvement of severe preoperative pain. In cases in which the humeral head cannot be dislocated due to severe dysplastic changes and joint line medialization, humeral resurfacing arthroplasty allows prosthetic placement through nontraditional exposures and results in high patient satisfaction and excellent pain relief.

Moderate to large engaging Hill-Sachs defects: an in vitro biomechanical comparison of the remplissage procedure, allograft humeral head reconstruction, and partial resurfacing arthroplasty.

BACKGROUND: The management of engaging Hill-Sachs defects (HSD) is controversial. The purpose of this study was to biomechanically compare 3 treatment strategies. MATERIALS AND METHODS: Eight specimens were tested on a shoulder simulator. The protocol involved testing 2 unrepaired HSD (30% and 45%), which were then treated with remplissage, humeral head allograft (HHA), and partial resurfacing arthroplasty (PRA). Stability (defect engagement and glenohumeral stiffness) and range of motion (ROM) were measured. RESULTS: All 30% and 45% HSDs engaged and dislocated. Remplissage and HHA effectively prevented engagement in all specimens; however, 62% of PRA engaged. No repair exhibited stiffness significantly greater than intact, but 30% and 45% remplissage produced a 74% and 207% increase, respectively, and were significantly greater than the unrepaired states (P ≤ .047). Stiffness results for HHA and PRA closely matched those of intact. In adduction, remplissage reduced internal-external ROM compared with both defects (P ≤ .01), but only 30% remplissage caused a significant decrease compared with intact (P = .049). In abduction, all repairs reduced ROM compared with HSD (P ≤ .04), but none compared with intact (P ≥ 0.05). In extension, remplissage had significantly less ROM than either HHA or PRA (P ≤ .02). CONCLUSION: All procedures improved stability; however, unlike remplissage, results from HHA and PRA closely resembled intact. Remplissage (30% and 45%) improved stability and eliminated engagement but caused reductions in ROM. HHA and PRA re-established intact ROM, but PRA could not fully prevent engagement. The effects of each technique are not equivalent and further studies are required.

The Plate-Joystick technique to reduce proximal humeral fractures and nonunions with a varus deformity through the extended deltoid-splitting approach.

Fractures and nonunions in which there is a varus deformity of the humeral head producing posterinferior subluxation of the articular surface are increasingly recognized as an important subgroup of proximal humeral fractures. Operative open reduction and internal fixation of these injuries is often recommended when the varus deformity is severe. We describe a simple technique to assist in the open reduction and locking plate stabilization of this challenging and complex fracture subtype using tools and implants that are readily available in most modern orthopaedic trauma operating rooms.

Postoperative malrotation of humeral shaft fracture after plating compared with intramedullary nailing.

OBJECTIVE: We supposed difference of rotation alignment of postoperative humeral shaft fracutres between open reduction and internal fixation (ORIF) and intramedullay nailing (IMN) could be identified and the difference might influence the involved shoulder. This study evaluated and compared the extent of malrotation and shoulder function after humeral shaft fractures treated operatively with IMN or ORIF. MATERIALS AND METHODS: Fifty humeral shaft fractures were randomly allocated into 2 groups. Group I underwent antegrade IMN and group II underwent ORIF. Malrotation was measured postoperatively by computed tomography scan (CT). Fracture union and functional outcomes were recorded at 12 months. RESULTS: The final analysis comprised 45 patients. Group I had lower functional scores than group II (P < .05). Internal malrotation of 20° or more (humeral head internally rotated) was found in 27.2% of group I patients, but there was no malrotation in group II. The internal and external range of motion of the involved shoulder was significantly correlated with the degree of malrotation (P < .01). DISCUSSION: This study comprehensively evaluated the degree of malrotation using CT scanning for every patient. These data bring to light some unexpected results about poor shoulder function and degeneration after humeral shaft fracture. The study can provide baseline data for larger series and longer follow-up periods. CONCLUSIONS: Patients who underwent IMN had lower functional scores and a decreased range of motion postoperatively and also had a greater degree of malrotation than the ORIF group, which had none. The degree of malrotation correlated with a decreased range of motion and may possibly be a reason for degenerative arthritis at long-term follow-up.