Original Article
Nonoperative Management of Posterior Shoulder Instability: An Assessment of Survival and Predictors for Conversion to Surgery at 1 to 10 Years After Diagnosis

https://doi.org/10.1016/j.arthro.2019.01.056Get rights and content

Purpose

To (1) define the rate of delayed surgery, between 1 and 10 years after injury, in a population-based study of patients with posterior shoulder instability (PSI), (2) evaluate predictive factors associated with delayed repair, and (3) identify differences between the nonoperative and operative groups at long-term follow-up.

Methods

A population-based retrospectively reviewed study of all patients with PSI from January 1, 1994, to December 31, 2015, was performed. Inclusion required a clinical diagnosis of PSI combined with supporting imaging. Complete medical records were reviewed for 2,091 potential cases. Kaplan-Meier estimates were used to calculate survival. Landmark survival analysis was performed to identify predictors of conversion to surgery.

Results

The study included 143 patients with PSI, 79 of whom were managed nonoperatively for at least 1 year after diagnosis. After the first year, survival free of surgery was 78.3% at 1 year, 63.1% at 5 years, and 51.5% at 10 years. There was a trend toward increased surgery in patients with a body mass index > 35 (P = .10; hazard ratio = 2.32; confidence interval, 0.8-6.8). Nonthrowing athletes (including contact/weight-lifting athletes) showed a trend toward an increased risk for surgery (P = .07). Patients who underwent surgery were significantly more likely to have progression in arthritis (P = .02; hazard ratio = 4.0; confidence interval, 1.2-13.2).

Conclusions

Nonoperative management was performed for at least 1 year in over half of patients diagnosed with PSI. Overall, long-term follow-up demonstrates that 46% of these patients converted to surgery between 1 and 10 years after initial diagnosis. Ultimately, 70% of patients diagnosed with PSI go on to surgical intervention. Patients who underwent surgery at any time point were at an increased risk of radiographic progression of arthritis at a minimum of 5 years of follow-up.

Level of Evidence

Level III, cohort study.

Section snippets

Methods

This population-based study was conducted in Olmsted County, Minnesota (2010 U.S. Census population: 144,260). Patients were identified through the Rochester Epidemiology Project, a medical records linkage system that provides access to complete medical records for all county residents from 1996 to the present.13 The methodology and generalizability of this epidemiological tool have previously been reported in detail.14, 15 A search for diagnostic codes related to PSI yielded 2,091 potential

Results

After review of all records, there were 143 patients with new-onset PSI between January 1, 1994, and December 31, 2015. A total of 64/143 (45%) patients elected to undergo early surgical intervention (<1 year). The remaining 79/143 (55%) patients were initially treated nonoperatively (minimum 1 year). There was no difference in patient demographics between those treated surgically in the first year and those who elected nonsurgical management (Table 1). The 79 patients initially treated

Discussion

Most patients (100/143, 70%) diagnosed with PSI ultimately underwent surgery. Our data demonstrate that although 55% (79/143) of patients elected nonoperative management for a minimum of 1 year, nearly half of these patients (36/79; 46%) converted to surgery between 1 and 10 years after a diagnosis of PSI. Patients who underwent surgery at any time point were at significantly increased risk for radiographic progression of osteoarthritis (P = .02, HR = 4.0) at a minimum 5 years of follow-up.

The

Conclusions

Nonoperative management was performed for at least 1 year in over half of patients diagnosed with PSI. Long-term follow-up demonstrates that 46% of these patients converted to surgery between 1 and 10 years after initial diagnosis. Ultimately, 70% of patients diagnosed with PSI required surgical intervention during the study period. Patients who underwent surgery at any time point were at an increased risk of radiographic progression of arthritis at a minimum of 5 years of follow-up.

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    The authors report the following potential conflicts of interest or sources of funding: D.L.D. is an editorial or governing board member of the AJSM Medical Publishing Board of Trustees, a board or committee member of the American Orthopaedic Society for Sports Medicine, a board or committee member of the NBA/GE Strategic Advisory Board, and receives research support from Arthrex, and D.L.D.’s spouse owns stock or stock options in and receives IP royalties from Tenex Health and Sonex Health. A.J.K. is a consultant for Arthrex, JRF Ortho, Vericel, Ceterix, and Histogenics and a board member of ISAKOS. Full ICMJE author disclosure forms are available for this article online, as supplementary material.

    This study was made possible using the resources of the Rochester Epidemiology Project, which is supported by the National Institute on Aging of the National Institutes of Health under Award Number R01AG034676. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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