Laminoplasty—an underutilized procedure for cervical spondylotic myelopathy

BACKGROUND CONTENTCervical laminoplasty (LP) and laminectomy and fusion (LF) are commonly used surgical techniques for cervical spondylotic myelopathy (CSM). Several recent studies have demonstrated superior perioperative metrics and decreased overall costs with LP, yet LF is performed far more often in the United States.PURPOSETo determine the percentage of patients with CSM who are radiographically candidates for LP.STUDY DESIGNRetrospective comparative cohort study.PATIENT SAMPLEPatients >18 years old who underwent LF or LP for CSM at 2 large academic institutions from 2017 to 2019.OUTCOME MEASURESCandidacy for LP based on radiographic criteria.METHODSRadiographs were assessed by 2 spine surgeons not involved in the care of the patients to determine the C2–C7 Cobb angle and the presence and extent of cervical instability. Patients with kyphosis >13°, > 3.5 mm of listhesis on static imaging, or > 2.5 mm of motion on flexion-extension or standing-supine films were not considered candidates for LP. Intraclass coefficient (ICC) was calculated to assess the interobserver reliability of angular measurements and the presence of instability. The percentage of patients for whom LP was contraindicated was calculated.RESULTSOne hundred eight patients underwent LF while 142 underwent LP. Of the 108 patients who underwent LF, 79.6% were radiographically deemed candidates for LP, as were all 142 patients who underwent LP. The ICC for C2–C7 alignment was 0.90; there was 97% agreement with respect to the presence of instability.CONCLUSIONSIn 250 patients with CSM, 228 (91.2%) were radiographically candidates for LP. These data suggest that LP may be an underutilized procedure for the treatment for CSM.     

The effects of body mass index and sex on impact force and effective pelvic stiffness during simulated lateral falls

BackgroundThe incidence of hip fractures is highest for underweight females with low body mass index (BMI). However, it is unknown how these factors influence impact dynamics during in-vivo lateral hip impacts. We used a pelvis release paradigm to compare: (1) absolute and normalized forces applied to the femur-pelvis system across sex and BMI groups; (2) the force-prediction accuracy of vibration-based versus force-deflection-based estimates of effective pelvic stiffness; and (3) effective pelvic stiffness between BMI and sex groups.MethodsTwenty-eight persons participated (7 low-BMI females, 7 low-BMI males, 7 high-BMI females, 7 high-BMI males, with BMI criteria of <22.5 and >28 for low- and high-BMI groups respectively). The participant's pelvis was released from heights of 0 to 5 cm. A force plate measured impact loads, while a motion capture system measured pelvic deflection.FindingsPeak impact forces were 22.6% higher, while normalized peak forces were 31.2% lower, for high- compared to low-BMI participants. Accuracy of peak force predictions improved by 25% for the force-deflection versus the vibration-based stiffness estimation method. Effective pelvic stiffness was greater for males than females, but no significant differences were observed between BMI groups.InterpretationThis study adds to clinical understanding of the effects of sex and BMI on impact dynamics during falls on the hip, and raises questions about the biomechanical mechanisms underlying the protective role of high BMI on hip fracture risk. Understanding the relationship between impact mechanics and faller characteristics should lead to more effective prevention of hip fractures.     

Outcome of radial head preserving operations in missed Monteggia fracture in children

Background:

The dislocated radial head in missed Monteggia fracture loses its concave articular surface and displays hypertrophic changes and flattened humeral capitellum configuration, thereby limiting the range of motion. We evaluated the results of open reduction in missed Monteggia fractures by various techniques.

Materials and Methods:

Sixty-three missed Monteggia fractures were included in the analysis. We performed four combinations of operation: Group I: 22 patients treated with modified Hirayama ulnar osteotomy plus annular ligament reconstruction with free Palmaris longus grafting; Group II:18 patients treated with modified Hirayama ulnar osteotomy plus annular ligament reconstruction by the Bell Tawse''s procedure; Group III-9: patients treated with only modified Hirayama''s osteotomy; and Group IV: 14 patients treated with transverse osteotomy of ulna and annular ligament reconstruction by the Bell Tawse''s procedure. During followup these cases were assessed for the following parameters: 1) range of motion and 2) mayo elbow performance index (MEPI). Results were noted on follow ups at 3, 6, 12 months and then on yearly basis. Sixty-three patients were followed up for an average duration of 5.6 years (range 3-8 years).

Results:

The mean range of motion was increased by 45°, 30°, 45°, 20° for Group I, II, III and IV respectively. The average increase in MEPI scores was also almost on the same lines. There was one case of frank dislocation in group III and six cases of subluxation, two each in Groups II, III, and IV. For Annular ligament reconstruction, amongst two procedures, Groups II and IV (Bell Tawse group), had a significant extension lag contributing to the lower increase in the range of motion as compared to the Palmaris longus reconstruction group (group I).

Conclusion:

Hirayama''s osteotomy is inherently more stable than the simple transverse osteotomy and it should be combined with annular ligament reconstruction. Palmaris longus graft for ligament reconstruction provides more stability as compare to Bell Towse''s procedure.