Calcium phosphate cement enhances the torsional strength and stiffness of high tibial osteotomies.

PURPOSE: There has been a resurgence in the use of opening wedge high tibial osteotomy (owHTO). Calcium phosphate cement has been shown to improve strength in compression for augmentation of tibial plateau and owHTO fixation. However, knee kinematics includes a torsional load during ambulation, which is as yet unstudied in this model. The purpose of this paper is to investigate the effect of injectable calcium phosphate cement on the biomechanical stability of standard high tibial osteotomy defect with applied torsional load and ultimate stiffness of the supporting construct. METHODS: Testing was performed on 22 bone mineral density-matched and age-matched cadaver specimens. Intact specimens were treated with 10° opening wedge osteotomies, identical surgical techniques as clinically used and fixation provided by iBalance© PEEK implant (Arthrex, Naples FL). Nine specimens were augmented with calcium phosphate injectable cement, Quickset (Arthrex Inc., Naples Fl). Constructs were for construct stiffness, torsional loads to failure, and mechanisms of failure. As a gold-standard comparison group, four samples were tested with a titanium, fixed angle device alone: Contourlock plate (Arthrex Inc., Naples Fl). RESULTS: Peak torque to failure was significantly greater in samples augmented with calcium phosphate bone cement (23.0 ± 9.6 Nm) compared with specimens fixed with PEEK implant alone (18.1 ± 7.3). Construct stiffness in torsion was also significantly improved with bone cement application (349.0 ± 126.8 Nm/°) compared with PEEK implant alone (202.2 ± 153.4 Nm/°) and fixed angle implant system (142.9 ± 74.7 Nm/°). CONCLUSION: Injectable calcium phosphate cement improves the initial maximal torsional strength and stiffness of high tibial osteotomy construct.

Radiographic prevalence of scaphotrapeziotrapezoid osteoarthrosis.

PURPOSE: To define the radiographic prevalence of scaphotrapeziotrapezoid (STT) osteoarthrosis (OA) in a cohort of patients presenting to a hand surgeon for any complaint. The secondary purpose was to evaluate coexisting thumb carpometacarpal (CMC) joint OA. METHODS: Seven hundred radiographs were evaluated for presence and degree of STT and thumb CMC arthritic changes in consecutive patients presenting to a hand clinic for any chief complaint over the study period. RESULTS: OA was noted at the STT joint in 111 of the 700 (16%) radiographs reviewed. Increased age, female sex, presence of a scapholunate (SL) ligament gap greater than 3 mm, and presence of radiographic thumb CMC joint OA were all significantly correlated with presence of STT joint OA. However, logistical regression analysis demonstrated that only increasing age, presence of an SL ligament gap greater than 3 mm, and presence of thumb CMC joint OA were strong predictors of STT joint OA. CONCLUSIONS: STT joint OA is a common finding on hand radiographs of patients presenting to a hand clinic. Its prevalence increases with age, the presence of an SL ligament gap greater than 3 mm, and with the presence of CMC joint OA. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Surgical treatment of osteoarthritis in the middle-aged athlete: new horizons in high tibial osteotomies.

Middle-aged athletes represent adults from the age of 35 to 60 years for the purposes of this discussion. The prevalence of knee osteoarthritis increases with age, and older people are staying active longer. The indications for opening wedge high tibial osteotomy (owHTO) continue to grow. owHTO correct malalignment to unload the medial joint in middle-aged athletes with a varus knee who want to return to high-impact activities. owHTO may be combined with cartilage preserving procedures, or with ligament reconstructions. We describe our preferred surgical technique and surgical implant with advanced guidance system to create predictable accurate results.