This edition of International Musculoskeletal Medicine includes a review of an article published 100 years ago by Goldthwait. He is considered to be one of the first to write about pathology of the facet or zygoapophysial joint (ZAJ) and back pain. Much has been discovered since then and, with the advent of Interventional radiology, treatment options now exist to treat patients with chronic lumbar spinal pain of ZAJ aetiology.
However several clinical questions arise:
| 1. | What is the prevalence of ZAJ pain in the population of chronic lumbar spinal pain patients? | ||||
| 2. | How can we accurately diagnose such cases? | ||||
| 3. | What are the best treatments for our patients with ZAJ pain? | ||||
Prevalence figures have been published by several authors using a technique of double blocks where local anaesthetic of different duration of effect is applied to the medial branches of the posterior primary ramus nerve or intra-articularly into the ZAJ. If pain is relieved in a manner that is consistent with the duration of the anaesthetic used on both occasions the diagnosis of ZAJ-related back pain is considered confirmed. Such published figures vary from between 15% in the younger population to more than 40% in the older population.Citation1–Citation3 Importantly, it seems that only 3% of patients have more than one ‘cause’ of pain,Citation4 although this surprisingly low figure needs to be confirmed in other studies. If that figure is correct, it implies that in 97% of cases we are looking for one pathological cause of the chronic lumbar spinal pain. Considering these prevalence figures, that exclude radicular cases, red flags, and in a population of older patients, a rough working average for clinical use is 40:40:20–40% of our chronic lumbar spine patients have discogenic pain, 40% have ZAJ pain and 20% have ‘other’ (which seems to be mainly sacro-iliac). So ZAJ pain, 4 patients out of 10, is going to be a fairly common presentation in our consulting rooms.
The next question is how to accurately identify such cases. Many studies have shown that there are no clinical signs and symptoms and examination techniques that can positively identify a ZAJ back pain case although some studies do suggest some symptoms and signs, such as pain with extension and rotation, can be helpful.Citation5,Citation6 Cadaver studies have shown that ZAJ arthrosis is 100% after the age of 60 and 50% from age 30, rendering investigations such as plain X-rays and CT of little value.Citation7 One would also wonder about the value of taking a history and examination but it is important in the aspect of detecting red flags and indeed it has a positive effect on the important patient/doctor relationship. So how can we detect these symptomatic ZAJ cases from the many asymptomatic arthrosis cases in a scientific way – should we blindly block medial branches from L5 up, or is there a more rational approach?
One solution to this clinical dilemma is the use of Single Photon Emission CT (SPECT) – this type of bone scan is a technique that uses relatively low doses of radiation and it has been shown to provide good anatomical localization, to reduce the number of injections required and can provide a superior clinical outcome. For a more detailed consideration of the use of SPECT including sensitivity and specificity I refer interested readers to an article published in the Australasian Musculoskeletal Medicine Journal recently.Citation8 A fairly recent study by Pneumaticos in 2006Citation9 in 47 patients indicates that by using SPECT to identify ZAJ cases 13 of 15 had improved pain at 1 month versus only 5 of 12 who did not have a SPECT performed. Another group with a negative SPECT had a response rate of only 2 of 16. The methodology used in this study, however, has been criticized and a follow-up study is needed.
The final question that arises is what treatment options are available that can help our patients with ZAJ pain. The two main options seem to be either a CT guided/fluoroscopic guided or even ultrasound guided, steroid, and local anaesthetic intra-articular injection, or a medial branch radio-frequency ablation (RFA) preceded by an anaesthetic trial block. Which to choose? The evidence indicates that RFA has a prolonged effect of up to 18 months, can be repeated if necessary,Citation10 has a low complication rate, and does relieve patient pain. The intra-articular injection is also a viable option to those patients who are reluctant to have ‘nerves burnt’, when RFA is not available, or even as a trial of treatment to further hone in on the cause of the pain. However, such a treatment only seems to last for about 3 months.Citation11 While the latter is a relatively short period of time, patients with chronic pain are grateful for even that and it provides them with a nebulous thing called ‘hope’ that something can indeed be done for them. As such it can be worthwhile in the absence of something better such as RFA.
In conclusion the facet joint is indeed more relevant than ever and we should acknowledge the likes of Goldthwait and Ghormley for their pioneering work. From the prevalence figures, in older patients, it is a common underlying cause of chronic lumbar spinal pain and SPECT seems to be a worthwhile investigation to detect such cases and effective treatment can follow from this investigation. Being able to provide our patients with a firm diagnosis in itself is useful, as it can confirm that they have a ‘real’ condition and this also can help to remove some of the stigma attached to suffering from chronic lumbar spinal pain.
References
- Depalma MJ, Ketchum JM, Saullo T. What is the source of chronic low back pain and does age play a role? Pain Med 2011;15(5):732–9.
- Manchikanti L, Pampati V, Fellows B, Bakhit CE. Prevalence of lumbar facet joint pain in chronic low back pain. Pain Physician 1999;2(3):59–64.
- Bogduk N. Management of chronic low back pain. Med J Aust 2004;180(2):79–83.
- Schwarzer AC, Wang SC, Bogduk N, McNaught PJ, Laurent R. Prevalence and clinical features of lumbar zygapophysial joint pain: a study in an Australian population with chronic low back pain. Ann Rheum Dis 1995;54(2):100–6.
- Revel M, Poiraudeau S, Auleley GR, Payan C, Denke A, Nguyen M, et al. Capacity of the clinical picture to characterize low back pain relieved by facet joint anesthesia. Proposed criteria to identify patients with painful facet joints. Spine 1998;23(18):1972–6; discussion 1977.
- Laslett M, McDonald B, Aprill CN, Tropp H, Oberg B. Clinical predictors of screening lumbar zygapophyseal joint blocks: development of clinical prediction rules. Spine J 2006;6(4):370–9.
- Eubanks JD, Lee MJ, Cassinelli E, Ahn NU. Prevalence of lumbar facet arthrosis and its relationship to age, sex, and race: an anatomic study of cadaveric specimens. Spine 2007;32(19):2058–62.
- Baster T. The patient who couldn't ride his Harley Davidson Motorbike – a case report and a literature review of the use of SPECT scans for the diagnosis of chronic low back pain arising from the zygoapophysial joints. Australas Musculoskelet Med 2011;16(1):13–6 (reprints of this are available by request from [email protected]).
- Pneumaticos SG, Chatziioannou SN, Hipp JA, Moore WH, Esses SI. Low back pain: prediction of short-term outcome of facet joint injection with bone scintigraphy. Radiology 2006;238(2):693–8.
- Rambaransingh B, Stanford G, Burnham R. The effect of repeated zygapophysial joint radiofrequency neurotomy on pain, disability, and improvement duration. Pain Med 2010;11(9):1343–7.
- Manchikanti L, Singh V, Falco FJE, Cash KA, Pampati V. Evaluation of lumbar facet joint nerve blocks in managing chronic low back pain: a randomized, double-blind, controlled trial with a 2-year follow-up. Int J Med Sci 2010;7(3):124–35.