title: How does back muscle strength change after posterior lumbar interbody fusion?
abstract: OBJECTIVE There is a lack of evidence of how back muscle strength changes after lumbar fusion surgery and how exercise influences these changes. The aim of this study was to evaluate changes in back muscle strength after posterior lumbar interbody fusion (PLIF) and to measure the effects of a postoperative exercise program on muscle strength and physical and mental health outcomes. METHODS This prospective study enrolled 59 women (mean age 58 years) who underwent PLIF at 1 or 2 spinal levels. To assess the effects of a supervised lumbar stabilization exercise (LSE), the authors allocated the patients to an LSE (n = 26) or a control (n = 33) group. The patients in the LSE group performed the LSEs between 3 and 6 months postoperatively. Back extensor strength, visual analog scale (VAS) scores in back pain, and physical component summary (PCS) and mental component summary (MCS) scores on the 36-Item Short Form Health Survey were determined for the both groups. RESULTS Mean strength of the back muscles tended to slightly decrease by 7.5% from preoperatively to 3 months after PLIF (p = 0.145), but it significantly increased thereafter and was sustained until the last follow-up (38.1%, p < 0.001). The mean back muscle strength was similar in the LSE and control groups preoperatively, but it increased significantly more in the LSE group (64.2%) than in the control group (21.7%) at the last follow-up 12 months after PLIF (p = 0.012). At the last follow-up, decreases in back pain VAS scores were more significant among LSE group patients, who had a pain reduction on average of 58.2%, than among control group patients (reduction of 26.1%) (p = 0.013). The patients in the LSE group also had greater improvement in both PCS (39.9% improvement) and MCS (20.7% improvement) scores than the patients in the control group (improvement of 18.0% and 1.1%, p = 0.042 and p = 0.035, respectively). CONCLUSIONS After PLIF, strength in back muscles decreased until 3 months postoperatively but significantly increased after that period. The patients who regularly underwent postoperative LSE had significantly improved back strength, less pain, and less functional disability at 12 months postoperatively.
authors.affiliation: Departments of 1 Orthopedic Surgery and.
authors.forename: Chong-Suh
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Kyung-Chung
authors.initials: KC
authors.lastname: Kang
authors.affiliation: Departments of 1 Orthopedic Surgery and.
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Chung
authors.affiliation: Physical Medicine and Rehabilitation.
authors.forename: Won-Hah
authors.initials: WH
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Won-Ju
authors.initials: WJ
authors.lastname: Shin
authors.affiliation: Division of Sports Medicine, Department of Physical Medicine and Rehabilitation, Samsung Medical Center, Sungkyunkwan University School of Medicine; and.
authors.forename: Yong-Gon
authors.initials: YG
authors.lastname: Seo
mesh_terms: D000328:Adult; D000368:Aged; D064131:Back Muscles / Q000503:physiopathology*; D001416:Back Pain / Q000503:physiopathology / Q000523:psychology / Q000601:surgery; D004185:Disability Evaluation; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000503:physiopathology / Q000523:psychology / Q000601:surgery*; D007537:Isometric Contraction; D008159:Lumbar Vertebrae / Q000601:surgery*; D008875:Middle Aged; D053580:Muscle Strength; D010147:Pain Measurement; D011446:Prospective Studies; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome
keywords: LSE = lumbar stabilization exercise; MCS = mental component summary; PCS = physical component summary; PLIF = posterior lumbar interbody fusion; QOL = quality of life; SF-36 = 36-Item Short Form Health Survey; VAS = visual analog scale; back muscle strength; change; lumbar; posterior lumbar interbody fusion; stabilization exercise