Manipulation under anesthesia (MUA) is a noninvasive treatment technique used to treat acute and chronic conditions, including muscular or spinal pain. Under anesthesia, spastic muscles are believed to relax and pain sensations diminish, which theoretically may permit joint manipulation through a full range of motion.

During manipulation under anesthesia, in addition to the manipulation, passive stretches and specific articular and postural kinesthetic maneuvers may be performed in order to break up fibrous adhesions and scar tissue around the spine and surrounding tissues.

Spinal manipulation under anesthesia (SMUA) has been used mostly by osteopaths and to a much lesser degree by orthopedists to treat spinal dysfunction. This procedure was typically performed in 1 single session. More recently, some chiropractors, with the assistance of anesthesiologists, have also employed this technique to alleviate acute and chronic neck and back pain.

The rationale for this approach is that fibrotic changes in the peri-articular and intra-articular soft tissues hinder movement, and sometimes it is necessary to anesthetize patients to reduce muscle tone and protective reflex mechanisms so that the spine can be manipulated effectively. This maneuver supposedly will break up adhesions within the surrounding spinal joints and stretch the restricting fibrotic tissue to a length compatible with motion, thereby, increasing joint function and reducing pain.

Within the realm of chiropractic, SMUA is generally performed daily for 1 to 5 consecutive days on an outpatient basis, and is followed by a post-SMUA rehabilitation regimen, which entails 1 week of daily manipulation to maintain joint mobility and avoid re-adhesion of fibrotic tissue. Anesthesia is usually induced by intravenous Pentothal (sodium thiopental), and manipulation of the affected joints takes about 7 to 10 minutes.

Although the risks associated with spinal manipulation and SMUA appear remote, serious complications following lumbar spinal manipulation, including massive cauda equina compression and vertebral pedicle fracture have been reported. For manipulation of the cervical spine, there is an increased chance of basivertebral and/or vertebral artery injury. Additionally, general anesthesia carries a small but clinically significant risk of anaphylaxis or malignant hyperpyrexia.

An assessment on SMUA (Kohlbeck and Haldeman, 2002) concluded that medicine assisted spinal manipulation therapies have a relatively long history of clinical use and have been reported in the literature for over 70 years. However, evidence for the effectiveness of these protocols remains largely anecdotal, based on case series mimicking many other surgical and conservative approaches for the treatment of chronic pain syndromes of musculoskeletal origin. There is, however, sufficient theoretical basis and positive results from case series to warrant further controlled trials on these techniques.

There is a lack of reliable evidence in the peer-reviewed published medical literature of the effectiveness of spinal manipulation under anesthesia. Evidence of spinal manipulation under anesthesia is of low quality, consisting primarily of case reports and uncontrolled case series. Limitations of current literature include small sample sizes, lack of random assignment, and limited evidence of durability. Other issues include uncertainties in patient selection criteria, and differences in protocols reported in studies, making generalizations difficult. Studies have reported on attendant risks of spinal manipulation (see., e.g., Dan & Saccasan, 1983, reporting on cases of serious complications after lumbar spinal manipulation, including massive cauda equina compression and vertebral pedicle fracture), and the risks of general anesthesia are well known. Guidelines from the American College of Occupational and Environmental Medicine (2007, 2008) and the Work Loss Data Institute (2011) state that spinal manipulation under anesthesia is not recommended.

In a prospective cohort study of 68 chronic low-back pain (LBP) patients, Kohlbeck et al (2005) measured changes in pain and disability for LBP patients receiving treatment with medication-assisted manipulation (MAM) and compared these to changes in a group only receiving spinal manipulation therapy (SMT). Outcomes were measured using the 1998 Version 2.0 American Association of Orthopaedic Surgeons/Council of Musculoskeletal Specialty Societies/Council of Spine Societies Outcomes Data Collection Instruments. The primary outcome variable was change in pain and disability. All patients received an initial 4- to 6-week trial of SMT, after which 42 patients received supplemental intervention with MAM and the remaining 26 patients continued with SMT. Low back pain and disability measures favored the MAM group over the SMT-only group at 3 months. This difference attenuated at 1 year. These investigators concluded that medication-assisted manipulation appears to offer some patients increased improvement in LBP and disability, and stated that further investigation of these apparent benefits in a randomized clinical trial is warranted.

Colorado Division of Workers' Compensation’s guidelines on "Low back pain medical treatment" (2014) did not recommend MUA.

Manipulation under anesthesia is not first-line therapy for frozen shoulder because, in most cases, frozen shoulder is a self-limited condition that responds well to conservative therapy. In addition, MUA can actually aggravate symptoms in some people, while others may develop a recurrence of adhesive capsulitis. Less than 10 % of patients will have long-term problems that require surgery or MUA (Anderson, 2008; Ogilvie-Harris et al, 1995).

Patients with frozen shoulder should be advised to limit overhead positioning, overhead reaching, and lifting during the acute period. A non-steroidal antiinflammatory drug (NSAID) may be prescribed for pain control. Exercise is the treatment of choice during the acute period; up to one-half of patients with frozen shoulder may be expected to respond to exercise therapy (van der Windt et al, 1998). Steroid injection may hasten recovery in persons with frozen shoulder who have concurrent rotator cuff and bicipital tendonitis (van der Windt et al, 1998), and the addition of supervised physical therapy following corticosteroid injection may result in more rapid improvement than injection alone (Carette et al, 2003). Glenohumeral intraarticular injection combined with saline dilation is indicated for patients with greater than 50 % loss of ROM despite a trial of physical therapy, subacromial injection, or both (Jacobs et al, 1991).

Referral for surgery is warranted in patients who fail to have an improvement in ROM by approximately 15 % per month with the above measures (Anderson, 2008). There are 2 main surgical approaches: arthroscopic dilation of the glenohumeral joint or MUA. The former is now more commonly performed than the latter. Newer arthroscopic techniques carry out a controlled capsular release rather than a forceful manipulation with its resultant uncontrolled tearing and bleeding.

A systematic review in BMJ Clinical Evidence (Speed, 2006) found that MUA plus intra-articular injection is "likely to be beneficial" for persons with frozen shoulder. The conclusions were based upon the results of 2 randomized controlled trials (RCTs). One RCT (n = 30) found that, in people with adhesive capsulitis, MUA plus intra-articular hydrocortisone injection increased recovery rates compared with intra-articular hydrocortisone injection alone at 3 months (Thomas et al, 1980). Another, weaker RCT (n = 98) found limited evidence that more people having MUA plus intra-articular saline injection than having manipulation alone or manipulation plus intra-articular injection of methylprednisolone had improvements in ROM, pain relief, and return to normal activities (Hamdan and Al Essa, 2003). The review noted that potential adverse effects of MUA of the shoulder include intra-articular lesions within the glenohumeral joint (Speed, 2006).

In a Cochrane review, Green et al (2000) examined the effectiveness of common interventions for shoulder pain. Intervention of interest included NSAIDs, intra-articular or subacromial glucocorticosteroid injection, oral glucocorticosteroid treatment, physiotherapy, MUA, hydrodilatation, or surgery. The authors concluded that there is little evidence to support or refute the effectiveness of common interventions for shoulder pain. They stated that there is a need for further well-designed clinical trials to establish a uniform method of defining shoulder disorders and developing outcome measures which are valid, reliable and responsive in these study populations.

Quraishi et al (2007) assessed the outcome of MUA and hydrodilatation as treatments for adhesive capsulitis. A total of 36 patients (38 shoulders) were randomized to receive either method, with all patients being treated in stage II of the disease process. The mean age of the patients was 55.2 years (44 to 70) and the mean duration of symptoms was 33.7 weeks (12 to 76). A total of 18 shoulders (17 patients) received MUA and 20 (19 patients) received hydrodilatation. There were 3 insulin-dependent diabetics in each group. The mean visual analog score (VAS) in the MUA group was 5.7 (3 to 8.5; n = 18) before treatment, 4.7 (0 to 8.5; n = 16) at 2 months (paired t-test p = 0.02), and 2.7 (0 to 9; n = 16) at 6 months (paired t-test, p = 0.0006). The mean score in the hydrodilatation group was 6.1 (4 to 10; n = 20) before treatment, 2.4 (0 to 8; n = 18) at 2 months (paired t-test, p = 0.001), and 1.7 (0 to 7; n = 18) at 6 months (paired t-test, p = 0.0006). The VAS in the hydrodilatation group were significantly better than those in the MUA group over the 6-month follow-up period (p < 0.0001). The mean Constant score in those manipulated was 36 (26 to 66) before treatment, 58.5 (24 to 90) at 2 months (paired t-test, p = 0.001) and 59.5 (23 to 85) at 6 months (paired t-test, p = 0.0006). In the hydrodilatation group it was 28.8 (18 to 55) before treatment, 57.4 (17 to 80) at 2 months (paired t-test, p = 0.0004) and 65.9 (28 to 92) at 6 months (paired t-test, p = 0.0005). The Constant scores in the hydrodilatation group were significantly better than those in the MUA group over the 6-month period of follow-up (p = 0.02). The ROM improved in all patients over the 6 months, but was not significantly different between the groups. At the final follow-up, 94 % of patients (17 of 18) were satisfied or very satisfied after hydrodilatation compared with 81 % (13 of 16) of those who received MUA. Most patients were treated successfully, but those undergoing hydrodilatation did better than those who underwent MUA.

Kivimäki and colleagues (2007) examined the effect of MUA in patients with frozen shoulder. A blinded randomized trial with a 1-year follow-up was performed at 3 referral hospitals. A total of 125 patients with clinically verified frozen shoulder were randomly assigned to the manipulation group (n = 65) or control group (n = 60). Both the intervention group and the control group were instructed in specific therapeutic exercises by physiotherapists. Clinical data were gathered at baseline and at 6 weeks and 3, 6, and 12 months after randomization. The 2 groups did not differ at any time of the follow-up in terms of shoulder pain or working ability. Small differences in the ROM were detected favoring the manipulation group. Perceived shoulder pain decreased during follow-up equally in the 2 groups, and at 1 year after randomization, only slight pain remained. Manipulation under anesthesia does not add effectiveness to an exercise program performed by patients.

Flannery et al (2007) examined the influence of timing of MUA for adhesive capsulitis of the shoulder on the long-term outcome. A total of 180 consecutive patients with a diagnosis of adhesive capsulitis according to Codman's criteria were selected from a shoulder surgery database; 145 were available for follow-up after a mean period of 62 months (range of 12 to 125). All patients underwent MUA with intra-articular steroid injection. A statistically significant improvement in range of movement, function (Oxford Shoulder Score) (OSS) and VAS was obtained following manipulation. Ninety percent of the 145 patients who successfully completed the study were satisfied with the procedure; 89 % indicated that they would choose the same procedure again if the same problem arose in the opposite shoulder. Eighty-three percent of the patients had MUA performed less than 9 months from onset of symptoms (early MUA). The remainder had MUA performed after 9 to 40 months (late MUA). Patients who had early intervention had a significantly better Oxford Shoulder Score at final follow-up; mobility and pain were also letter than in the late MUA group, but not significantly.

Manipulation under anesthesia has also been used to treat fibroarthrosis following total knee replacement. Following total knee arthroplasty, some patients who fail to achieve greater than 90 degrees of flexion in the early peri-operative period may be considered candidates for MUA of the knee. Manipulation under anesthesia is indicated in total knee arthroplasty having less than 90 degrees ROM 4 to 12 weeks following surgery, with no progression or regression in ROM (Pariente et al, 2006; Magit,et al, 2007).

Keating et al (2007) assessed the outcomes of manipulation following total knee arthroplasty. A total of 113 knees in 90 patients underwent manipulation for post-operative flexion of greater than or equal to 90 degrees at a mean of 10 weeks after surgery. Eighty-one (90 %) of the 90 patients achieved improvement of ultimate knee flexion following manipulation. The average flexion was 102 degrees prior to total knee arthroplasty, 111 degrees following skin closure, and 70 degrees before manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the 5-year follow-up was 35 degrees (p < 0.0001). The investigators reported that there was no significant difference in the mean improvement in flexion when patients who had manipulation within 12 weeks post-operatively were compared with those who had manipulation more than 12 weeks post-operatively. Patients who eventually underwent manipulation had significantly lower pre-operative Knee Society pain scores (more pain) than those who had not had manipulation (p = 0.0027). The investigators concluded that manipulation generally increases ultimate flexion following total knee arthroplasty. They noted that patients with severe pre-operative pain are more likely to require manipulation.

Available evidence for MUA for temporomandibular joint syndrome is limited to small, uncontrolled studies with limited follow-up. Foster et al (2000) conducted an uncontrolled prospective study of manipulation of the temporomandibular joint under anesthesia. The investigators reported that, of the 55 patients invited to participate in this study, 15 improved, 15 did not, 6 showed partial improvement, and 19 were not treated. The median pre-treatment opening was 20 mm (range of 13 to 27). Among those who improved after manipulation, the median opening after treatment was 38 mm (range of 35 to 56). The investigators reported that some of those who improved experienced a return of TMJ clicking but not of joint or muscle tenderness.

There is a paucity of evidence supporting the use of MUA for the treatment of disorders of other body joints such as the hip, ankle, knee, and wrist.

The National Academy of Manipulation Under Anesthesia Physicians' protocols for performing serial MUA (2002) stated that if the patient regains 80 % or more of normal biomechanical function during the first procedure and retains at least 80 % of functional improvement during post MUA evaluation, then serial MUA is usually unnecessary if post MUA therapy and rehabilitation is performed.

Araghi et al (2010) have used a technique of elbow examination (manipulation) under anesthesia in select patients after surgical release to assess the smoothness of the articulation, evaluate stability, and to stretch the flexion and rotation arcs. The study comprised 51 consecutive patients who underwent an examination under anesthesia between January of 1996 and December of 2001. The examination occurred a mean of 40 days after surgery. Forty-four patients with a minimum of 12 months follow-up revealed a mean pre-examination arc of 33 degrees, which improved to 73 degrees at the final assessment. Three patients had no appreciable change (less than 10 degrees ) in the total arc, and 1 patient lost motion. Four patients underwent a second examination under anesthesia at a mean of 119 days after the first examination. The average pre-examination arc of 40 degrees increased to 78 degrees at the final assessment (mean improvement of 38 degrees). The only complication was worsening of ulnar paresthesias in 3 patients; with 2 resolving spontaneously, and 1 requiring anterior ulnar nerve transposition. The authors concluded that examination (manipulation) under anesthesia can be a valuable adjunctive procedure to help regain the motion obtained at the time of surgical release. Moreover, they stated that because this was not a controlled series, additional studies might be conducted to refine those not benefiting from this procedure.

The U.S. Food and Drug Administration's labeling of Xiaflex (collagenase

for Dupuytren's contracture requires a finger extension procedure for persistent palpable cord, which is described in the labeling as a passive extension of a finger for 20 seconds. Local anesthetic may be used with this procedure. The finger extension procedure may be repeated a 2nd or 3rd time at 5- to 10-min intervals. However, manipulation under general anesthesia is not necessary to accomplish this procedure.

Xiong and colleagues (1998) stated that manipulation under anesthesia (MUA) is an important method to reduce cervical spinal dislocations in the acute stage. Causes of failure have not been clearly identified and neurological complications can be the major concern. All cervical dislocations have been traditionally treated by MUA in the Christchurch Spinal Injuries Unit as the primary treatment. These researchers reviewed all 31 patients treated from 1991 to 1995, with detailed documentation of neurological progression and final outcome. Three patterns were identified: bilateral dislocation, uni-facet dislocation, and fracture dislocation. Most of the dislocations (74 %) were successfully reduced by manipulation alone with minimum complications. The remaining 26 % patients required open reduction. The predominant causes of failure of reduction by manipulation were co-existing fractures. The success rate of reduction by manipulation was 90 % for pure bi-facet and uni-facet dislocations, but was only 22 % for the fracture dislocations. The authors concluded that MUA is a safe and effective procedure for pure cervical spinal dislocations. Fractures related to the dislocation should be identified early and open reduction be considered.

Also, an UpToDate review on "Evaluation and acute management of cervical spinal column injuries in adults" (Kaji and Hockberger, 2013) does not mention the use of MUA as a management tool.

The Washington State Department of Labor and Industries’ guideline on"Shoulder conditions diagnosis and treatment"(2013) recommended MUA for arthroscopic capsular release when conventional x-rays do not show bone pathology that can explain the loss of motion and patients have tried and failed 12 weeks of conservative care (including at least active assisted range of motion and home-based exercises).

Bealey and associates (2020) stated that frozen shoulder causes pain and stiffness. It affects around 10 % of individuals in their 50s and is slightly more common in women. Costly and invasive surgical interventions are used, without high-quality evidence that these are effective. In a parallel-group, open-label, 3-arm, multi-center, randomized superiority trial with unequal allocation (2 : 2 : 1), these researchers compared the clinical effectiveness and cost-effectiveness of 3 treatments in secondary care for adults with frozen shoulder; to qualitatively examine the acceptability of these treatments to patients and health-care professionals; and to update a systematic review to explore the trial findings in the context of existing evidence for the t3 treatments. An economic evaluation and a nested qualitative study were also Performed. Participants were adults (aged greater than or equal to 18 years) with unilateral frozen shoulder, characterized by restriction of passive external rotation in the affected shoulder to less than 50 % of the opposite shoulder, and with plain radiographs excluding other pathology. The inventions were early structured physiotherapy with a steroid injection, MUA with a steroid injection and arthroscopic capsular release followed by manipulation. Both of the surgical interventions were followed with post-procedural physiotherapy. The primary endpoint was the OSS at 12 months post-randomization. A difference of 5 points between early structured physiotherapy and MUA or arthroscopic capsular release or of 4 points between MUA and arthroscopic capsular release was judged clinically important. The mean age of the 503 participants was 54 years; 319 were women (63 %) and 150 had diabetes (30 %). The primary analyses comprised 473 participants (94 %). At the primary endpoint of 12 months, participants randomized to arthroscopic capsular release had, on average, a statistically significantly higher (better) OSS than those randomized to MUA (2.01 points, 95 % confidence interval [CI]: 0.10 to 3.91 points; p = 0.04) or early structured physiotherapy (3.06 points, 95 % CI: 0.71 to 5.41 points; p = 0.01); MUA did not result in statistically significantly better OSS than early structured physiotherapy (1.05 points, 95 % CI: -1.28 to 3.39 points; p = 0.38). No differences were deemed of clinical importance. Serious adverse events (SAEs) were rare but occurred in participants randomized to surgery (arthroscopic capsular release, n = 8; MUA, n = 2). There was, however, 1 SAE in a participant who received non-trial physiotherapy. The base-case economic analysis showed that MUA was more expensive than early structured physiotherapy, with slightly better utilities. The incremental cost-effectiveness ratio for MUA was £6,984 per additional quality-adjusted life-year (QALY), and this intervention was probably 86 % cost-effective at the threshold of £20,000 per QALY. Arthroscopic capsular release was more costly than early structured physiotherapy and MUA, with no statistically significant benefit in utilities. Participants in the qualitative study wanted early medical help and a quicker pathway to resolve their shoulder problem. A total of 9 studies were identified from the updated systematic review, including UK FROST, of which only 2 could be pooled, and found that arthroscopic capsular release was more effective than physiotherapy in the long-term shoulder functioning of patients, but not to the clinically important magnitude used in UK FROST. The authors concluded that none of the 3 interventions was clearly superior. Early structured physiotherapy with a steroid injection was an accessible and low-cost option; MUA was the most cost-effective option; while arthroscopic capsular release carried higher risks and higher costs.

Post-Traumatic Elbow Stiffness

Increased Need for Manipulation Under Anesthesia for patients Who Undergo Open Versus Arthroscopic Rotator Cuff Repair

In a retrospective, cohort study, Wang et al (2022) compared 90-day post-operative complications, healthcare use, 2-year and 5-year rates of re-operation and MUA, as well as costs at the 30-day, 90-day, and 1-year post-operative intervals following open and arthroscopic rotator cuff repair (RCR). Patients who underwent an open or arthroscopic RCR with minimum 5-year follow-up were identified in a national database (PearlDiver Technologies) using Common Procedural Terminology and International Classification of Diseases codes. These patients were then stratified into 2 cohorts: open RCRs and arthroscopic RCRs. These cohorts were propensity-matched based on age, sex, Charlson Co-morbidity Index, smoking status, and obesity (body mass index [BMI] greater than 30); 90-day medical complications, 2-year and 5-year surgical complications, and reimbursements at the 30-day, 90-day and 1-year post-operative intervals were assessed. Bi-variate statistics were carried out using χ2 tests, Fisher exact tests, and Student t-tests where appropriate. Reimbursements included the reimbursement for the index surgery as well as any reimbursements during the specified post-operative interval related to the index surgery. A total of 3,266 patients who underwent open RCR were matched with 3,266 patients who underwent arthroscopic RCR. Compared with patients who underwent arthroscopic RCR, patients who underwent open RCR were at significantly increased risk of 90-day surgical-site infection (0.89 % versus 0.34 %, p = 0.004), undergoing MUA within 2 years of surgery (1.65 % versus 0.95 %, p = 0.012), and undergoing MUA within 5 years of surgery (1.75 % versus 1.10 %, p = 0.028). There were no significant differences in any other post-operative complications, re-operation rates, or reimbursements between open RCR and arthroscopic RCR (all, p > 0.05). The authors concluded that patients undergoing open RCR were at increased risk of 90-day surgical-site infection and MUA both within 2 years and within 5 years of surgery in this study cohort. Level of Evidence = III.

Outcomes and Complications of Inlay Versus Onlay Patello-Femoral Arthroplasty

In a systematic review, Familiari et al (2023) examined outcomes and complications rates between inlay and onlay patella-femoral arthroplasty (PFA). According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a total of 42 studies with 2,552 patients were included. Data considered for quantitative analysis consisted of the Knee Society Score (KSS), the ROM, the VAS, and the Western Ontario and McMaster Universities questionnaire (WOMAC). Complications and revision surgery were considered. Data on post-operative KSS showed no differences between the groups. The ROM was evaluated in 8 studies for 70 and 331 inlay and onlay PFA, respectively. Onlay group was favorable in terms of post-operative ROM. Post-operative VAS was available for 64 inlay and 110 onlay and no differences were found. Data on post-operative WOMAC were available for 49 inlay and 527 onlay PFA and inlay group showed better scores. A statistically significant higher rate of instability, persistent pain, malposition, stiffness, deep infection, disease progression, and wear of the patellar component were noted in the inlay group. A higher rate of lateral release was noted in the onlay group. A higher number of MUA was noted in the inlay group. The revision to total knee arthroplasty (TKA) was reported more frequently in the inlay group. The authors concluded that a higher rate of conversion to TKA and complication rates after inlay technique was found. The potential of achieving better WOMAC scores with the inlay technique should be weighed against the higher complication and revision rates compared to the onlay technique. Level of Evidence = IV.

Appendix

MUA is considered medically necessary for chronic, refractory frozen shoulder (adhesive capsulitis) that meets the following criteria:

Scope of Policy

This Clinical Policy Bulletin addresses manipulation under general anesthesia.

Medical Necessity

Aetna considers manipulation under general anesthesia (MUA) medically necessary for the following indications:

Experimental and Investigational

The following MUA indications are considered experimental and investigational because the effectiveness of these approaches has not been established (not an all-inclusive list):

Policy Limitations and Exclusions