Ont Health Technol Assess Ser. 2004; 4(2): 1–39.

Peripheral nerve blocks improve both pain control and functional outcomes following total knee arthroplasty (TKA). However, few studies have examined the effects of different peripheral nerve block protocols on postoperative range of motion. The present study assessed the impact of a single-shot femoral nerve block (SFNB) versus continuous femoral nerve block (CFNB) on postoperative range of motion and the need for subsequent manipulation following TKA. Methods: We retrospective reviewed patient charts to identify patients who had undergone primary elective unilateral TKA by 2 surgeons at a high-volume orthopaedic specialty hospital over a 3-year period. A total of 1,091 patients received either SFNB or CFNB and were included in the data analysis. Identical surgical techniques, postoperative oral analgesic regimens, and rehabilitation protocols were used for all patients. Patients with <90° of flexion at 6 weeks postoperatively underwent closed manipulation under anesthesia (MUA). Results: Overall, 608 patients (55.7%) received CFNB and 483 patients (44.3%) received SFNB. Overall, 94 patients (8.6%) required postoperative manipulation for stiffness, including 36 (5.9%) in the CFNB group and 58 (12%) in the SFNB group. The 50% reduction in the need for manipulation in the CFNB group was independent of primary surgeon (p > 0.05). No significant differences were observed between the groups in terms of postoperative range of motion, either at the time of discharge or at 6 weeks postoperatively. A history of knee surgery, decreased preoperative range of motion, and decreased range of motion at the time of discharge were significantly associated with the need for further MUA (p = 0.0002, p < 0.0001, and p < 0.0001, respectively). Conclusions: Despite similar final postoperative range of motion between patients in both groups, our results suggest that CFNB may be superior to SFNB for reducing the need for postoperative manipulation after primary TKA. Furthermore, a history of ipsilateral knee surgery, decreased preoperative range of motion, and decreased range of motion at the time of discharge were identified as independent risk factors for postoperative stiffness requiring MUA after primary TKA. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Medical Advisory Secretariat
Hip Knee

Objective

The Medical Advisory Secretariat undertook a review of the evidence on the effectiveness and cost-effectiveness of computer assisted hip and knee arthroplasty. The two computer assisted arthroplasty systems that are the topics of this review are () navigation and () robotic-assisted hip and knee arthroplasty.

The Technology

Computer-assisted arthroplasty consists of navigation and robotic systems.

Surgical navigation is a visualization system that provides positional information about surgical tools or implants relative to a target bone on a computer display. Most of the navigation-assisted arthroplasty devices that are the subject of this review are licensed by Health Canada.

Robotic systems are active robots that mill bone according to information from a computer-assisted navigation system. The robotic-assisted arthroplasty devices that are the subject of this review are not currently licensed by Health Canada.

Review Strategy

The Cochrane and International Network of Agencies for Health Technology Assessment databases did not identify any health technology assessments on navigation or robotic-assisted hip or knee arthroplasty. The MEDLINE and EMBASE databases were searched for articles published between January 1, 1996 and November 30, 2003. This search produced 367 studies, of which 9 met the inclusion criteria.

Summary of Findings

Navigation-Assisted Arthroplasty

  • Five studies were identified that examined navigation-assisted arthroplasty.
  • A Level 1 evidence study from Germany found a statistically significant difference in alignment and angular deviation between navigation-assisted and free-hand total knee arthroplasty in favour of navigation-assisted surgery. However, the endpoints in this study were short-term. To date, the long-term effects (need for revision, implant longevity, pain, functional performance) are unknown.()
  • A Level 2 evidence short-term study found that navigation-assisted total knee arthroplasty was significantly better than a non-navigated procedure for one of five postoperative measured angles.()
  • A Level 2 evidence short-term study found no statistically significant difference in the variation of the abduction angle between navigation-assisted and conventional total hip arthroplasty.()
  • Level 3 evidence observational studies of navigation-assisted total knee arthroplasty and unicompartmental knee arthroplasty have been conducted. Two studies reported that “the follow-up of the navigated prostheses is currently too short to know if clinical outcome or survival rates are improved. Longer follow-up is required to determine the respective advantages and disadvantages of both techniques.”(;)

Robotic-Assisted Arthroplasty

  • Four studies were identified that examined robotic-assisted arthroplasty.
  • A Level 1 evidence study revealed that there was no statistically significant difference between functional hip scores at 24 months post implantation between patients who underwent robotic-assisted primary hip arthroplasty and those that were treated with manual implantation.()
  • Robotic-assisted arthroplasty had advantages in terms of preoperative planning and the accuracy of the intraoperative procedure.()
  • Patients who underwent robotic-assisted hip arthroplasty had a higher dislocation rate and more revisions.()
  • Robotic-assisted arthroplasty may prove effective with certain prostheses (e.g., anatomic) because their use may result in less muscle detachment.()
  • An observational study (Level 3 evidence) found that the incidence of severe embolic events during hip relocation was lower with robotic arthroplasty than with manual surgery.()
  • An observational study (Level 3 evidence) found that there was no significant difference in gait analyses of patients who underwent robotic-assisted total hip arthroplasty using robotic surgery compared to patients who were treated with conventional cementless total hip arthroplasty.()
  • An observational study (Level 3 evidence) compared outcomes of total knee arthroplasty between patients undergoing robotic surgery and patients who were historical controls. Brief, qualitative results suggested that there was much broader variation of angles after manual total knee arthroplasty compared to the robotic technique and that there was no difference in knee functional scores or implant position at the 3 and 6 month follow-up.()

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