Problems with ACL brace design and sizing the path to custom design

Abstract:

The anterior cruciate ligament is the most commonly injured knee ligament in the population, therefore referrals for bracing to stabilise this ligament are common. They are also usually paired with other ligament involvement which makes bracing very individual. The patient we are focusing on in the case study had difficulty with bracing which lead to various surgeries which were unsuccessful. Due to the patients anatomy the knee braces she has tried were uncomfortable and difficult to fit. This lead to the measurement for a full custom fit ACL brace which has fulfilled the patients' goals of treatment and lead to no further surgical management.

Introduction

ACL rupture is a common knee injury with an annual incidence in the general population of approximately 1 in 3500, although the actual incidence may be higher (Gordon et al, 2004. Albright et al, 1999). This is a common injury and is usually combined with other ligament instability when focusing on sports and falls related trauma (Bispo et al, 2008).

A person who has torn their ACL has 15 times greater risk of a second ACL injury during the initial 12 months after ACL reconstruction, and risk of ACL injury to the opposite knee is two times that of the restructured knee (Paterno, 2013. Wrights, 2011). This generates a large number of patients to require bracing after surgery to aid stability and recovery. Graft strength of the new ACL is considerably weaker that the native ACL during the first 12 months, so a brace during this early period helps protect it from harmful forces that occur in everyday life or in sport. 

Case Presentation

Trust: Durham and Darlington NHS

Underlying condition: Right ACL rupture and multi ligament damage.

Previous medical history: 3 ACL reconstruction surgeries. Meniscal tears and MCL and LCL damage. Unstable patella with tendency to dislocate. 

Patient's Problems: Patient has had difficulty with her right knee over the past several years. She has had 3 surgeries on the knee and would like to avoid further surgical intervention as the past experiences have not been pleasant. She had tried a Donjoy style of brace a few years ago as an initial brace but found this uncomfortable especially at the back of the calf area. The patient is a hairdresser and is on her feet majority of the day, this causes a lot of pain and also the knee can give way randomly which has knocked her confidence. It is very important for the patient to maintain her mobility level and continue to work. 

As the patients main discomfort with previous bracing was the posterior aspect around the calf area, a design change was needed to relieve this area. Pt has a bulky calf muscle which causes the problem with fit. The CTI OTS brace is an anterior shell frame with only the straps contacting the posterior leg which would seem to suit the patients' needs more. Patient's size lay between small and medium and both were tried and returned due to ill fitting. The small was putting a lot of pressure on the lateral tibial plateau area and the medium was not supporting at all.

The patient is also very aware of the bulk of the brace and the aesthetics of the brace are important to her and her lifestyle.

Orthotic prescription: Measured for CTI OTS custom brace. The reasoning behind going for a custom fitting brace was the abnormality in the patients' knee joint centre width in comparison to her calf muscle circ. These two measurements where not marrying up which was causing problems to achieve an optimum fit for the patient. Patient also had previous difficulty with braces with posteriorly placed framework, therefore CTI design was best suited but stock measures of this brace were not. Hence measurement for MTM CTI. Bioskin knee sleeve also ordered to provide compression control of the patella.

Manufacturing/Procurement

The patient was measured for a custom brace using an app which takes photographs of the leg in the correct planes and positions. Additional measurements were taken by the Orthotists using a tape measure. The patient then had a broader range of colours to choose from which she was much more pleased about. This was ordered and delivered through Ossur directly. Manufactured in Florida and delivered in 10 days.

Review and Outcome

Patient reviewed after 4 weeks and she has been on holiday with the brace during this time. She reported the brace was so much lighter and more comfortable than all previous and she felt secure and confident when wearing the brace. She found it much easier to fit under clothes and also was not self-conscious about wearing it over leggings, which she had been with previous bracing. Overall much more happy and is managing lifestyle well around the brace. She wears it for work every day and it has made a great improvement in work life. Pt cancelled appointment with orthopaedic surgeon after this as she had no interest in any further surgical intervention due to compliance with brace.

Reflection

In reflection of the process I will now be much more confident in distinguishing when a patient will and will not fit into a stock brace. It has increased my knowledge behind the measurement of custom bracing and the advantages of it for particular patients. Overall I feel that it was the correct choice to provide this patient with a MTM brace due to her anatomical features and expectations from the brace. The patient has been through various unsuccessful surgeries and her confidence in the healthcare treatment she was being provided with was very low. She was getting very depressed and her mobility level was dropping as she could not get relief on her right side from anything. Although it was a slightly longer process to get measured and fitted as myself and the rep from Ossur had to be present, it was worth it for the patient satisfaction level. Overall her mobility level has increased and her pain level has decreased which has led to discharge from orthopaedics and increase in general health. 

Author: Ruth Haughey

References:

Gordon MD, Steiner ME.. Anterior cruciate ligament injuries. In: Orthopaedic Knowledge update Sports Medicine III, Garrick JG (ED), American Academic of Orthopaedic Surgeons, Rosemont 2004. p.169.

Albright jC, Carpenter JE, Graf BK, et al.. Knee and leg : soft tissue trauma. In: Orthopaedic Knowledge Update 6, Beaty JH (Ed), American Academy of Orthopaedic Surgeons, Rosemont 1999. p.533

Bispo Jr RZ, Kawano CT, Guedes AV. Clinics.1 Vol. 63. Sao Paulo: 2008. Chronic multiple knee ligament injuries: epidemiological analysis of more than one hundred cases; pp. 3-8.

Paterno MV. Paper #2. Presented AOSSM Annual Meeting; July 11-14, 2013; Chicago

Wright RW, Magnussen RA, Dunn WR, Spindler KP, Ipsilateral Graft and Contralateral ACL Rupture at Five Years or More Following ACL Reconstruction. Journal of Bone and Joint Surgery, Am. 2011;93:1159-1165