March 2011 Newsletter from Malik Slosberg, DC, MS

Senna MK, Machaly , SA. Does ‘maintained’ spinal manipulation therapy for chronic non-specific low back pain result in better long term outcome? Spine 2011;36: epub ahead of print.

Hopayian, K et al. The clinical features of the piriformis syndrome: a systematic review. Euro Spine J 2010; 19:2095-2109.
Greetings to everyone and a warm welcome to all those new subscribers to the monthly Research Update. Remember that on my website, www.slosberg.com, are posted many recent studies for you to review for free. Hope you find the material informative and helpful. Please let other chiropractors know about this free service.

Today is March 21 and here are two new studies. They cover two different topics. The first is a very important addition to the chiropractic database which examines the benefits of spinal manipulation (SM) compared to sham manipulation for nonspecifc chronic LBP. In addition, it evaluates the use of maintenance SM to determine if it improves long-term outcomes after a relatively intensive 4 week SM treatment plan. The findings demonstrate the benefits of both short-term SM care versus a placebo and the long-term advantages of a miantenance SM program. The second study is the most recent (December 2010) and comprehensive review of the "Piriformis Syndrome" - what are the clinical indicators, how is it diagnosed, what are the mechanisms, is there a gold-standard to identify and differeniate this non-spinal cause of sciatica? I hope you find the following information informative and clinically relevant.

Senna MK, Machaly , SA. Does ‘maintained’ spinal manipulation therapy for chronic non-specific low back pain result in better long term outcome? Spine 2011;36: epub ahead of print.

This is a randomized, placebo controlled study to assess the effectiveness of spinal manipulation (SM) for non-specific chronic LBP (=/>6 mo) in 60 patients (Pts), as well as, the effectiveness of maintenance care in long-term reduction of pain & disability.

Pts were randomized into 3 Groups:
Group 1: 12 sham SM over 1 month,
Group 2: 12 SM visits over 1 month,
Group 3: 12 SM visits over 1 month + maintenance care (1 visit every 2 weeks for 9 months).

Outcomes: Oswestry, SF-36, Patient’s Global Assessment of Pain, Modified Schober’s Test, Lateral Flexion.

Results: Both SM without maintenance care & SM with maintenance care were significantly better on all outcome measures than the sham group at 1 month of follow-up, but only SM with maintenance care was significantly better on all outcome measures at 10 months of follow-up. Pts with maintenance SM had significantly lower pain and disability scores compared to the sham and SM without maintenance care at long-term follow-up.

Conclusions: SM is effective for nonspecific CLBP. To obtain long-term benefit, this study suggests maintenance SM after the initial intensive manipulative care.

Commentary: This is an important new study in the journal ‘Spine’ which demonstrates in a relatively small, but randomized controlled trial two key findings.

  1. Pts receiving a relatively intensive SM protocol of 3 visits/week for 4 weeks did significantly better on all outcome measures than the sham group at one month follow-up. This finding clearly documents that SM is effective for nonspecific CLBP and improves multiple outcomes compared to the same number of sham visits.
  2. The finding that SM with maintenance care was significantly better than either the sham or the initial 12 visits of SM in one month on both pain and disability at 10 months follow-up indicates that maintenance care (1 visit every 2 weeks for 9 months) may be necessary to achieve optimal long-term benefits from SM.

The sustained and progressive improvements in pain and disability scores over the subsequent 9 months of follow-up (see attached graphs) document the value of maintenance care.

Graphs of 10 months of follow-up for control, no maintained SM, & maitained SM care for CLBP patients:

Senn_pain_chart_w_maintenance_care.2

Seena_Disability_chart_maintenance_care.1



Hopayian, K et al. The clinical features of the piriformis syndrome: a systematic review. Euro Spine J 2010; 19:2095-2109.

Piriformis syndrome (PS), originally proposed in 1934, is defined as sciatica caused by compression of the sciatic nerve by the piriformis muscle, and has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. This review included all studies up to March 2008 and consists of 55 studies.

The most common features of Piriformis Syndrome:

  • Buttock pain (usually worse than LBP),
  • External tenderness over the greater sciatic notch,
  • Aggravation of the pain through sitting,
  • Augmentation of the pain with maneuvers that increase piriformis muscle tension .

Proposed mechanisms for PS include:

  • Contracture or spasm of the PM from trauma,
  • Predisposition to nerve compression by congenital variations of the sciatic nerve or PM, in which the sciatic nerve or its divisions pass through the belly or tendinous portions of a normal muscle or the bellies of a bifid muscle.
  • Overuse and hypertrophy.

A review of general population surveys of sciatica:

  • Lifetime prevalence of 12.2–27%,
  • Annual prevalence 2.2–19.5%
  • Point prevalence1.6–4.8%.
  • The proportion due to herniated disc remains uncertain.
  • In a series of 160 sciatica Pts, only 131 Pts (82%) had herniated disc MRI.
  • The significant minority of people with sciatica but no spinal cause (whether disc or spinal stenosis) points to the need for research on extraspinal causes of sciatica.

There is no accepted investigation that can act as the reference standard for PS.
There is no reliable method of diagnosis.

Confirmed Muscle-Based Piriformis Syndrome:

  1. Sciatic Pts who responded to local anesthetic and steroid injections into the PM.
  2. Pts who respond to surgical correction: excision of calcified muscle, surgical division of piriformis.

Commentary: This thorough review of the literature points out the current status of the diagnosis of piriformis syndrome as very difficult to confirm. There is no gold standard; there is no objective clinical test to verify the diagnosis as accurate. An important indicator would be the failure to identify on MRI the presence of a herniated disc or spinal stenosis at the level and side of neurologic localizing signs. 18% of sciatic patients failed to demonstrate either a herniated disc or spinal stenosis on MRI indicating that the cause of the complaints may be extraspinal in origin.The four common features consistent with piriformis syndrome clinically suggest the likelihood that a patient's clinical presentation may be due to piriformis syndrome. Additionally, a beneficial response to local anesthetic and steroid injections into the piriformis muscle may help confirm the diagnosis.