O’Driscoll, Shawn W.

Periosteal transplantation is being used clinically to repair articular defects. Isolated cells and very small periosteal explants can be grown in tissue culture, but it will be necessary to test larger sizes for tissue engineering to be applied to clinical transplantation of periosteum. This study was conducted to assess the chondrogenic potential of different sizes of periosteal explants in agarose culture. Ninety-six rabbit tibial periosteal explants in three different sizes (small 1.5 × 2, medium 3 × 2, and large 4 × 6 mm, 32 pieces per size) were cultured in agarose suspension for 6 wk and given TGF-β1 (10 ng/mL) for the first 2 wk. Tissue growth, as indicated by normalized final wet weights of the explants after 6 wk in culture, was inversely proportional to explant size. Cartilage formation was observed in all explante. Histomorphometry revealed that cartilage formation was significantly better for the smaller explants (80% cartilage), but similar in the medium and larger explants (60% cartilage). Similar proportions of type II collagen were present in the different-sized explants. This study demonstrates that various sizes of periosteal explants can be grown in culture. Abundant cartilage was produced even by the large explants. © 1998 Elsevier Science Inc.

Abstract Reconstruction of the lateral ulnar collateral ligament of the elbow is the primary treatment for recurrent symptomatic posterolateral rotatory instability. Although a number of lateral ulnar collateral ligament reconstruction techniques have been described, the docking technique has received general acceptance. In this technique, the graft is passed through a tunnel on the ulnar side and the 2 free limbs are docked into the humerus at the isometric point on the lateral condyle. Advantages of this method of reconstruction include reduced bone removal, decreased soft tissue damage, and precise control of graft tensioning. When precise surgical steps are followed, this technique can be performed in a reliable, efficient, and reproducible manner for patients with posterolateral rotatory instability of the elbow. Technique Video video See video under supplementary data.

Normative data are useful for assessing isometric shoulder strength in patients with bilateral shoulder abnormalities. The purpose of this study was to develop a normative database for shoulder strength in the clinically relevant positions and movements. Twenty combinations of exertions and postures—including flexion, extension, abduction, adduction, internal rotation, and external rotation—were tested for both the dominant and nondominant sides. Strength was measured isometrically using a modified Cybex II dynamometer. The cross-sectional study design included 120 subjects (60 women and 60 men) ranging in age from 20 to 78 years from southern Minnesota. Tables of normative strength data were constructed. Multivariate analyses were performed to assess the effect of age, sex, and weight on strength. Age was negatively associated with all strength measures, and weight was positively associated with them. Men were stronger than women when controlling for age and weight. Statistically significant differences between dominant and nondominant shoulders were found for only some of the strength measures taken. These normal data will be useful to the clinician, as they permit a standard against which to compare shoulder strength.

Periosteal autografts have the potential to regenerate articular cartilage defects, but this potential is limited by the patient's age. Allograft transplantation from a young donor to an older recipient might bypass this limitation. The effect of the time delay, between death and harvesting of a periosteal graft, on the chondrogenic potential of periosteum is important not only for transplantation but also for studies dealing with tissues retrieved postmortem (i.e., including the periosteal explant model). The purpose of this study was to investigate the chondrogenic potential of periosteum obtained postmortem and a possible beneficial effect of hypothermia. Thirty NZ white rabbits (2 months old) were sacrificed and stored at room temperature or 4°C for 0, 4, 6, 8, 12, 16, 18, or 24 h. Periosteal explants were then obtained and a standard cartilage yield assay performed by culturing them for 6 weeks using the periosteal organ culture model as previous published. TGF-β1 (10 ng/ml) was added for the first 14 days of culture. Histochemical analysis and quantitative collagen typing were performed. In the explants from the animals kept for 4 h at room temperature growth and chondrogenesis were dramatically reduced. Little or no chondrogenesis was seen in expiants from rabbits maintained at room temperature after 4–8 h (or more) postmortem. Cooling the rabbits to 4°C partially prevented this loss of viability and continued to do so for 24 h. Even storage at 4°C did not eliminate the decrease in chondrogenic potential, though it did permit partial preservation of chondrogenic potential. If periosteum is to be used for allograft transplantation, or if it is used for experimental study, its viability must be assured. This is best accomplished by harvesting it immediately postmortem. Preservation techniques, cryopreservation, or hypothermia might be useful in preserving periosteal chondrogenic potential.

Objectives To determine the ability to sonographically identify the posterior cutaneous nerve of the forearm (PCNF) and its distal epicondylar branches using sonographically guided perineural injections in an unembalmed cadaveric model. Methods A single experienced operator used a 12–3‐MHz linear array transducer to identify the PCNF and its distal epicondylar region branches in 10 unembalmed cadaveric specimens (6 right and 4 left) obtained from 10 donors. Sonographically guided perineural PCNF injections were then completed with a 22‐gauge, 38‐mm stainless steel needle to deliver 0.25 mL of 50% diluted colored latex at 3 points along the PCNF. The latex location was then confirmed via dissection. Results The 10 donors included 4 male and 6 female cadavers aged 48 to 94 years (mean, 73 years) with body mass indices of 19 to 37 kg/m 2 (mean, 26 kg/m 2 ). The operator sonographically identified the PCNF and several distal branches traversing over or directly adjacent to the lateral epicondyle in all 10 specimens. Only 7 of 10 specimens showed a distinct PCNF bifurcation into anterior and posterior divisions, and all 7 were accurately identified and localized on sonography. There was no evidence of latex overflow to clinically relevant adjacent structures or injury to regional vessels or nerves. Conclusions High‐resolution sonography can identify the PCNF and its distal epicondylar branches. Sonographic evaluation of the PCNF should be included in the evaluation of patients presenting with refractory or atypical lateral elbow pain syndromes. Diagnostic and therapeutic sonographically guided procedures targeting the PCNF or its lateral epicondylar branches are feasible and warrant further investigation.

Abstract Posterolateral rotatory instability (PLRI) is the most commonly encountered pattern of elbow instability. It is the result of disruption of the lateral collateral ligament complex leading to a posterolateral rotatory subluxation of the ulna and radial head. A number of examination maneuvers have been described to assist in clinical identification of PLRI. Despite this, some inconsistency in the description of these techniques remains in the orthopaedic literature. This Technical Note details the mechanism of injury and patient presentation, and emphasizes the primacy of the posterolateral rotatory drawer test in the assessment of PLRI while providing video instruction on how it should be performed. Technique Video video See video under supplementary data.

Abstract Currently, a number of examination and imaging techniques exist for diagnosing posterolateral rotatory instability of the elbow. Although the posterolateral rotatory drawer is the primary examination maneuver, other special tests include the lateral pivot‐shift test, prone push‐up test, chair push‐up test, and tabletop push‐up test. In addition, posterolateral rotatory instability can be evaluated using radiography, magnetic resonance imaging, dynamic fluoroscopy, or dynamic ultrasound. In this Technical Note, each of these tests is described in detail. Video instruction is also provided to further explain the techniques and provide examples of positive tests. Technique Video video See video under supplementary data.

ObjectivesWe sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling.Materials and MethodsAdult sheep were randomly assigned to one of three groups (n = 8/group): 1. trabecular metal/periosteal graft (TMPG), 2. trabecular metal (TM), 3. empty defect (ED). Cartilage and bone healing were assessed macroscopically, biochemically (type II collagen, sulfated glycosaminoglycan (sGAG) and double-stranded DNA (dsDNA) content) and histologically.ResultsAt 16 weeks post-operatively, histological scores amongst treatment groups were not statistically different (TMPG: overall 12.7, cartilage 8.6, bone 4.1; TM: overall 14.2, cartilage 9.5, bone 4.9; ED: overall 13.6, cartilage 9.1, bone 4.5). Metal scaffolds were incorporated into the surrounding bone, both in TM and TMPG. The sGAG yield was lower in the neo-cartilage regions compared with the articular cartilage (AC) controls (TMPG 20.8/AC 39.5, TM 25.6/AC 33.3, ED 32.2/AC 40.2 µg sGAG/1 mg respectively), with statistical significance being achieved for the TMPG group (p < 0.05). Hypercellularity of the neo-cartilage was found in TM and ED, as the dsDNA content was significantly higher (p < 0.05) compared with contralateral AC controls (TM 126.7/AC 71.1, ED 99.3/AC 62.8 ng dsDNA/1 mg). The highest type II collagen content was found in neo-cartilage after TM compared with TMPG and ED (TM 60%/TMPG 40%/ED 39%). Inter-treatment differences were not significant.ConclusionsTM is a highly suitable material for the reconstitution of osseous defects. TM enables excellent bony ingrowth and fast integration. However, combined with autologous periosteum, such a biocomposite failed to promote satisfactory neo-cartilage formation. Cite this article: E. H. Mrosek, H-W. Chung, J. S. Fitzsimmons, S. W. O’Driscoll, G. G. Reinholz, J. C. Schagemann. Porous tantalum biocomposites for osteochondral defect repair: A follow-up study in a sheep model. Bone Joint J 2016;5:403–411. DOI: 10.1302/2046-3758.59.BJR-2016-0070.R1.

Purpose To report the safety of using the proximal anteromedial portal, using a simplified ulnar nerve management strategy derived from an earlier study, in a series of patients with previously transposed ulnar nerves. Methods A retrospective review of all elbow arthroscopies performed by a single surgeon from 2009 to 2014 was performed. The following techniques were used if, by palpation, localization of the ulnar nerve was considered to be certain (group 1) or uncertain (group 2): In group 1 (certain) the proximal anteromedial portal was established in the normal antegrade fashion. In group 2 (uncertain) a 1‐ to 3‐cm incision was made at the planned proximal anteromedial portal site, and blunt dissection down to the capsule was performed without identification of the nerve. The nerve was not visualized but sometimes was palpated through the wound to confirm its location anteriorly or posteriorly. If there was a disparity between the prior operative records and the physical examination findings, the nerve was explored through a 3‐ to 4‐cm incision. Results We reviewed 394 elbow arthroscopy cases, 22 of which had a prior transposed ulnar nerve (21 subcutaneous and 1 submuscular) that required anterior‐compartment arthroscopic surgery. Group 1 (certain location) consisted of 9 elbows (41%), whereas group 2 (uncertain location) consisted of 13 (59%). In 2 cases in group 2, the ulnar nerve was explored because of the disparity between the previous medical records and the physical examination findings. There were no operative ulnar nerve injuries related to the use of the proximal anteromedial portal. Conclusions The proximal anteromedial portal was able to be used safely in patients with prior transposition of the ulnar nerve. This was achieved by using an algorithm based on the degree of certainty with which the nerve can be localized in the region of the planned portal by clinical palpation. Level of Evidence Level IV, therapeutic case series.

Snapping elbow is a well‐known condition where elbow flexion and extension elicits a painful, popping sensation. The most frequent etiology is anterior dislocation of the ulnar nerve over the medial epicondyle. Four patients (3 females and 1 male) presented with complaints of a popping sensation in the elbow, pain over the medial aspect of the forearm, and ulnar neuritis. All patients underwent preoperative dynamic ultrasound and surgical exploration of the medial elbow. Intraoperatively, snapping of the MABC over the medial epicondyle was discovered in all four patients. In three patients, there was abnormal displacement of the medial triceps and ulnar nerve: in two of these, both structures dislocated over the medial epicondyle and in one patient both structures subluxated. In each case, the MABC was decompressed (n = 1) and transposed (n = 3), and in three cases, the medial triceps and ulnar nerve were addressed as well. Symptomatic improvement was achieved in all cases. Retrospective review of the ultrasound revealed the snapping MABC, though it was less effective prospectively in the cases when snapping MABC was not suspected. In conclusion, snapping of the MABC broadens the spectrum of disorders that results in snapping elbow. To our knowledge, we are unaware of prior reports of this entity. Clin. Anat. 28:872–877, 2015. © 2015 Wiley Periodicals, Inc.