The Effect of Teriparatide on the Hip: A Literature Review

Differential effects of teriparatide, denosumab and zoledronate on hip structural and mechanical parameters in osteoporosis; a real-life study

PURPOSE

The aim of this study was to evaluate changes in hip geometry parameters following treatment with teriparatide (TPD), denosumab (Dmab) and zoledronate (ZOL) in real-life setting.

METHODS

We studied 249 patients with osteoporosis (OP) with mean [SD] age of 71.5 [11.1] years divided into 3 treatment groups; Group A received TPD; n = 55, Group B (Dmab); n = 116 and Group C (ZOL); n = 78 attending a routine metabolic bone clinic. Bone mineral density (BMD) was measured by DXA at the lumbar spine (LS), total hip (TH) and femoral neck (FN) prior to treatment and after 2 years (Group A), after a mean treatment duration of 3.3 [1.3] years (Group B) and after 1, 2 and 3 doses of ZOL (Group C) to assess treatment response. Hip structural analysis (HSA) was carried out retrospectively from DXA-acquired femur images at the narrow neck (NN), the intertrochanter (IT) and femoral shaft (FS).

RESULTS

Changes in parameters of hip geometry and mechanical strength were seen in the following treatment. Percentage change in cross-sectional area (CSA): 3.56[1.6] % p = 0.01 and cross-sectional moment of inertia (CSMI): 4.1[1.8] % p = 0.029 increased at the NN only in Group A. Improvement in HSA parameters at the IT were seen in group B: CSA: 3.3[0.67]% p < 0.001, cortical thickness (Co Th): 2.8[0.78]% p = 0.001, CSMI: 5.9[1.3]% p < 0.001, section modulus (Z):6.2[1.1]% p < 0.001 and buckling ratio (BR): - 3.0[0.86]% p = 0.001 with small changes at the FS: CSA: 1.2[0.4]% p = 0.005, Z:1.6 [0.76]%, p = 0.04. Changes at the IT were also seen in Group C (after 2 doses): CSA: 2.5[0.77]% p = 0.017, Co Th: 2.4[0.84]% p = 0.012, CSMI: 3.9[1.3]% p = 0.017, Z:5.2[1.16]% p < 0.001 and BR: - 3.1[0.88]% p = 0.001 and at the NN (following 3 doses): outer diameter (OD): 4.0[1.4]% p = 0.0005, endocortical diameter(ED): 4.3[1.67% p = 0.009, CSA:5.2[1.8]% p = 0.003, CSMI: 9.3[3.8]% p = 0.019.

CONCLUSIONS

Analysis of the effect of OP therapies on hip geometry is useful in understanding the mechanisms of their anti-fracture effect and may provide additional information on their efficacy.

Initiation of Bisphosphonates Prior to Total Joint Arthroplasty Does Not Lower Periprosthetic Fracture Risk

BACKGROUND

Many patients are diagnosed with osteoporosis shortly prior to scheduling total joint arthroplasty (TJA). The purpose of this study was to determine if initiation of bisphosphonates prior to TJA decreased the risks of periprosthetic fractures (PPFx).

METHODS

A national database was used to identify all patients diagnosed with osteoporosis prior to primary TJA. Patients who had osteoporosis without preoperative bisphosphonate use were designated as our control group. Patients on preoperative bisphosphonates were stratified based on duration and timing of bisphosphonate use: long-term preoperative users (initiation 3 to 5 years preoperatively), intermediate-term preoperative users (initiation 1 to 3 years preoperatively), and short-term preoperative users (initiation 0 to 1 year preoperatively). Rates of PPFx at 90-day and 2-year follow-up were compared between groups.

RESULTS

In patients undergoing primary total hip arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .12) and 2-year follow-up (P = .22). In patients undergoing primary total knee arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .76) and 2-year follow-up (P = .39).

CONCLUSIONS

In patients undergoing primary TJA, preoperative bisphosphonate users did not have a decreased PPFx rate compared to our control group at 90-day and 2-year follow-up. Our findings suggest that preoperative bisphosphonate use, regardless of the duration of treatment, does not confer protective benefits against PPFx in patients undergoing TJA.

LEVEL OF EVIDENCE

Prognostic Level III.

Management of Osteoporosis Medication after Osteoporotic Fracture

The aim of this study was to provide helpful information for use in selection of an appropriate medication after osteoporotic fractures through conduct of a literature review. In addition, a review of the recommendations of several societies for prevention of subsequent fractures was performed and the appropriate choice of medication for treatment of atypical femur fractures was examined. Clinical perspective was obtained and an updated search of literature was conducted across PubMed and MEDLINE and relevant articles were selected. The articles were selected manually according to relevance, and the references for identified articles and reviews were also evaluated for relevance. The following areas are reviewed: Commonly prescribed osteoporosis medications: BPs (bisphosphonates), denosumab, and SERMs (selective estrogen receptor modulators) in antiresorptive medications and recombinant human parathyroid hormone teriparatide, recently approved Romosuzumab in anabolic agents, clinical practice guidelines for the management of osteoporosis, osteoporotic fracture, and atypical femur fracture. Most medications for treatment of osteoporosis do not delay fracture healing and the positive effect of teriparatide on fracture healing has been confirmed. In cases where an osteoporotic fracture is diagnosed, risk assessment should be performed for selection of very high-risk patients in order to prevent subsequent fractures, and administration of anabolic agents is recommended.