Severe traumatic valgus instability of the elbow: pathoanatomy and outcomes of primary operation

Operative treatment of Mason Type III radial head fractures - A comparative analysis using PROMIS

Objectives

The purpose of this study is to evaluate the outcomes of operatively treated Mason Type III radial head fractures. Additionally, this project seeks to assess efficacy of PROMIS in evaluating post-operative outcomes for this patient population.

Methods

A total of 143 patients who underwent operative treated Mason Type III radial head fractures were analyzed retrospectively. PROMIS physical function (PF), PROMIS upper extremity (UE), PROMIS pain interference (PI), demographic variables, and range of motion were collected and analyzed over 12-month follow-up.

Results

Radial head arthroplasty (RHA) was performed on 89 patients, open reduction and internal fixation (ORIF) was performed on 47 patients, and radial head excision was performed on 7 patients. Among the RHA patients, PROMIS PF, PI and UE demonstrated a change of -1.33 (p < 0.05), -1.48 (p < 0.05), and 2.23 (p < 0.05) respectively from injury to 12-months. Among the ORIF patients, PROMIS PF, PI and UE demonstrated a change of 3.22 (p < 0.05), -1.56 (p < 0.05), and 2.09 (p < 0.05) respectively from injury to 12-months. At the pre-operative and 12-month visits, the RHA group demonstrated lower PROMIS PF scores 34.75 vs 38.02 (p < 0.05) and 33.42 vs 41.24 (p < 0.05) respectively. Ther was no difference in PROMIS PI, UE, or elbow range of motion between the two groups at 6- or 12-month follow-up (p > 0.05).

Conclusion

Comparing the RHA and ORIF groups, there was no difference in PROMIS PI or UE scores nor was there a clinically significant improvement at the 6- or 12-month mark. The ORIF group demonstrated improved PROMIS PF at all follow-up periods and did show a clinically significant improvement. Patient Acceptable Symptom State (PASS) correlated only with PROMIS UE at 6- and 12- months for both groups.

Knuckle-walking in Sahelanthropus? Locomotor inferences from the ulnae of fossil hominins and other hominoids

Because the ulna supports and transmits forces during movement, its morphology can signal aspects of functional adaptation. To test whether, like extant apes, some hominins habitually recruit the forelimb in locomotion, we separate the ulna shaft and ulna proximal complex for independent shape analyses via elliptical Fourier methods to identify functional signals. We examine the relative influence of locomotion, taxonomy, and body mass on ulna contours in Homo sapiens (n = 22), five species of extant apes (n = 33), two Miocene apes (Hispanopithecus and Danuvius), and 17 fossil hominin specimens including Sahelanthropus, Ardipithecus, Australopithecus, Paranthropus, and early Homo. Ulna proximal complex contours correlate with body mass but not locomotor patterns, while ulna shafts significantly correlate with locomotion. African apes' ulna shafts are more robust and curved than Asian apes and are unlike other terrestrial mammals (including other primates), curving ventrally rather than dorsally. Because this distinctive curvature is absent in orangutans and hylobatids, it is likely a function of powerful flexors engaged in wrist and hand stabilization during knuckle-walking, and not an adaptation to climbing or suspensory behavior. The OH 36 (purported Paranthropus boisei) and TM 266 (assigned to Sahelanthropus tchadensis) fossils differ from other hominins by falling within the knuckle-walking morphospace, and thus appear to show forelimb morphology consistent with terrestrial locomotion. Discriminant function analysis classifies both OH 36 and TM 266 with Pan and Gorilla with high posterior probability. Along with its associated femur, the TM 266 ulna shaft contours and its deep, keeled trochlear notch comprise a suite of traits signaling African ape-like quadrupedalism. While implications for the phylogenetic position and hominin status of S. tchadensis remain equivocal, this study supports the growing body of evidence indicating that S. tchadensis was not an obligate biped, but instead represents a late Miocene hominid with knuckle-walking adaptations.

TREATMENT OF SIMPLE CHRONIC INSTABILITY OF THE ELBOW JOINT

Simple chronic instability of the elbow joint is one of the urgent problems in modern traumatology due to the fact that the standard tactics of managing patients with traumatic injuries of the elbow joint due to dislocation, which amounts to its elimination, immobilization of the upper limb and subsequent development of movements in the joint, most often does not take into account damage to specific soft tissue structures. With untimely treatment for qualified help, with late or unsuccessful attempts to eliminate dislocation of the bones of the forearm, less often with chronic traumatization of the ligamentous apparatus of the elbow joint during some types of occupation, one of the most unpleasant complications may form, namely, chronic instability. This article discusses the main types of chronic instability of the elbow joint, analyzes approaches to the management of patients with simple chronic instability. Despite the not very high occurrence of this pathology, the effectiveness of modern surgical treatment options aimed at reconstruction of the ligamentous apparatus of the elbow joint, the percentage of unsatisfactory results of treatment of simple chronic recurrent and persistent instability of the elbow joint remains high.

Role of the transverse ligament of the ulnar collateral ligament of the elbow: a biomechanical study

Background

The ulnar collateral ligament (UCL) complex of the elbow plays a primary role in valgus and posteromedial stability of the elbow. The anterior oblique ligament (AOL) of the UCL is believed to provide the majority of resistance to external forces on the medial elbow. The transverse ligament (TL) of the UCL is generally thought to have minimal contribution to the elbow’s overall stability. However, recent studies have suggested a more significant role for the TL. The primary aim of this study was to identify the TL’s contribution to the stability of the elbow joint in determining the joint stiffness and neutral zone variation in internal rotation.

Methods

Twelve cadaveric elbows, set at a 90° flexion angle, were tested by applying an internal rotational force on the humerus to generate a medial opening torque at the level of the elbow. The specimens were preconditioned with 10 cycles of humeral internal rotation with sinusoidal torque ranging from 0 to 5 Nm. Elbow stiffness measures and joint neutral zone were first evaluated in its integrity during a final ramp loading. The test was subsequently repeated after cutting the TL at 33%, 66%, and 100% followed by the AOL in the same fashion.

Results

The native UCL complex joint stiffness to internal rotation measured 1.52 ± 0.51 Nm/°. The first observable change occurred with 33% sectioning of the AOL, with further sectioning of the AOL minimizing the joint stiffness to 1.26 ± 0.32 Nm/° (P = .004). A 33% resection of the TL found an initial neutral zone variation of 0.376 ± 0.23° that increased to 0.771 ± 0.41° (P < .01) at full resection. These values were marginal when compared with the full resection of the AOL for which we have found 3.69 ± 1.65° (P < .01).

Conclusion

The TL had no contribution to internal rotation elbow joint stiffness at a flexion angle of 90°. However, sequential sectioning of the TL was found to significantly increase the joint neutral zone when compared with the native cadaveric elbow at a flexion angle of 90°. This provides evidence toward the TL having some form of contribution to the elbow’s overall stability.