We present a consecutive series of 99 arthroscopic capsule releases with a mean follow-up period of 28 months. This cohort gave patient
reported outcome measures and satisfaction scores that reflect an excellent outcome following an anterior capsule and rotator interval release
with a manipulation to achieve a full range of movement intra-operatively. Oxford Shoulder Score went from a mean of 23 pre-operatively
to 44 post-operatively. At a mean of four months, satisfaction score was 9/10, 88% had returned to work, 92% reported an improvement in
the quality of their sleep and 94% stated that they would have the procedure again. No difference was found between those that did receive
steroid injections at the time of surgery and those that did not and there was no trend for diabetic patients to do worse than their non-diabetic
contemporaries.
Keywords : Frozen Shoulder; Adhesive Capsulitis; Arthroscopic Capsule Release; PROMs
Introduction
Primary frozen shoulder is characterised by pain and global
stiffness of the shoulder in the presence of a normal shoulder
radiograph, with the histological findings of chronic inflammation
and fibrosis [1-3]. With a prevalence of approximately 2% in the
adult population [1], it is most commonly seen in middle-aged
women [4] and though mainly idiopathic, it is more common in
diabetics [5-7] who have a 40% chance of developing a frozen
shoulder in their lifetime [1,5,6]. There is an association with
Dupuytren’s contracture [2,8,9], thyroid dysfunction [10,11] and
a genetic role has been implicated [2].
Although the natural history of primary frozen shoulder is
believed to be self-limiting, resolution of symptoms may take
more than three years and there remains a group of patients
with residual pain, stiffness and loss of function in the long-term.
Patients with the most severe symptoms at onset carry a worse
prognosis [3,12].
Patients who have undergone multiple interventions
including bee venom acupuncture, anti-inflammatory medication,
corticosteroid injection, manipulation under anaesthesia
(MUA) and extensive physiotherapy prior to surgery dilute the
understanding of the benefits of arthroscopic capsular release
itself. Some would argue that these must be tried prior to the offer of surgical intervention. Several studies have also used outcome
measures that have not been validated, making it difficult to
derive valid conclusions.
Surgical treatment of primary frozen shoulder has evolved in
the last 20 years. Open surgical release of the rotator interval was
popularised by Ozaki et al. [13] in 1989 and later by others [14].
Improving arthroscopic techniques in the shoulder have reduced
the morbidity of open procedures and arthroscopic capsular
release was proposed 15 years ago as a minimally invasive
surgical option for treatment of frozen shoulder by Ogilvie-Harris et al. [15]. This procedure has since been reported by a
number of authors with reliably good outcomes [16-19]. Many
studies have reported small numbers with mixed patient groups,
often including cases of secondary frozen shoulder.
In one of the first prospective reports, Reeves [20] followed
41 patients for between 5 and 10 years, reporting significant
recovery in range of movement in most patients at a mean of
30.1 months post onset of symptoms. In 1992, Shaffer et al. [21]
reported that in a series of 62 patients from an initial cohort of
183 patients, 50% had pain or stiffness at a mean of seven years
and 60% had restriction of movement. They had all undergone
shoulder rehabilitation exercises supplemented by various
treatment regimes, including subacromial injection (84%) and
MUA (6.2%). Manipulation under anaesthetic for frozen shoulder has been shown to be an effective treatment for this condition,
but can require excessive force to tear the fibrotic capsular
tissue resulting in reported complications such as humeral shaft
fracture, brachial plexus or vascular injury, rotator cuff tear and
dislocation. Much like cutting half way through a piece of paper
before trying to tear it in two, controlled surgical release of the
worst affected frozen shoulder tissue in the rotator interval
greatly reduces the force required to achieve an effective MUA,
thereby reducing the complication rate.
Ogilvie-Harris et al compared MUA with arthroscopic release
in a prospective cohort of 40 patients [15]. Their results after a
follow-up of between two and five years showed a similar range
of movement, but the release had a better outcome in terms of
pain and function. The overall outcome was excellent in 15 of 20
patients in the arthroscopic group but in only seven of 18 in the
MUA group. Klinger et al. [22] performed arthroscopic release on
36 shoulders after failure of conservative treatment of 6 months
duration and reported that 75% of their patients returned back
to work within a mean of 8 weeks after release.
In a larger series of 73 patients Watson et al. [23] discharged
all their patients with full range of movement and without pain
at a mean of 8.9 weeks after release, results which have not been
matched in the literature. The mean duration of conservative
treatment in their series was 18 months. In a recent retrospective
review of 115 patients who underwent arthroscopic release for
refractory shoulder stiffness of varying aetiology, Elhassan et al.
[24] reported improvement of age- and gender-adjusted Constant
score from 35% to 86% at a mean follow up of 46 months. In their
study only 41 patients (36%) belonged to primary idiopathic
group who had failed a trial of conservative therapy for a mean
of 11 months. The authors reported maximum improvement in
this subgroup of patients compared to post-surgical and posttraumatic
groups.
Controversy exists as to how much of the capsule to release
arthroscopically since similar results have been demonstrated
in studies where circumferential release has been performed
compared to only a rotator interval release. In the above
series [24], the authors performed both anterior and posterior
release. In a retrospective comparative analysis of data from
48 consecutive patients who underwent capsular release for
resistant primary or secondary frozen shoulder, Snow et al.
[25] evaluated the benefit of additional posterior release over
standard antero-inferior release, concluding that there was no
significant difference in the overall outcome with the addition of
a posterior release. Jerosch et al. [26] also reported no additional
advantage with the extension to a global 360° capsular release
compared with a 270° release. Cadaveric study shows that the
axillary nerve runs closest to the inferior glenoid rim between
the 5:30 and 6:00 o’clock position and that its closest distance
from the glenoid rim varied from 10 to 25mm in the neutral arm
position [27]. Pearsall et al. [19] described releasing the intraarticular
portion of the subscapularis [19]; however, most studies
show excellent results without subscapularis release.
Use of intra-articular administration of steroids during
frozen shoulder surgery is standard practice in some centres [14,28]. In 25 patients with primary frozen shoulder undergoing
arthroscopic release, Bunker et al routinely instilled 10 mL of
0.5% bupivacaine and 25 mg hydrocortisone acetate through
the arthroscopic cannula before withdrawal from the joint. 88%
reported dramatic improvement in pain and function within the
first two weeks of release [14].
Diabetes mellitus is recognized as a poor prognostic
indicator in frozen shoulder, however the reported outcome of
arthroscopic capsular release in patients with this disease varies
in the literature [7,23,24,29]. Some reviews reported a higher
recurrence rate after arthroscopic capsular release in diabetic
patients, whereas others did not find a difference in the outcome
between diabetic patients and non-diabetic patients.
The importance of PROMs in elective orthopedics has
been highlighted by the Department of Health in the NHS
Next Stage Review and their widespread use has been
recommended [30]. The use of PROMs in assessment of
surgical results is enormously useful; however combining
this with patient satisfaction questions may add significant
value to the interpretation of outcome after surgery [2].
Aim
The aim of this study is to report the functional outcome of arthroscopic release in primary frozen shoulder using validated patient-reported outcome measures (PROMs) and a patient satisfaction index.
Methods
Study Population
Between 2002 and 2009, 132 consecutive patients (135 shoulders) identified in a specialist shoulder clinic with a diagnosis of primary frozen shoulder unresponsive to conservative management underwent arthroscopic capsular release and manipulation. Patients with a secondary frozen shoulder, for example post-traumatic, post-surgical or from bony structural abnormalities were excluded from the study, as were all cases in which a secondary procedure was performed to include sub-acromial decompression. All patients were treated with an initial outpatient conservative regimen of intra-articular glenohumeral injection of local anaesthetic and steroid followed by supervised physical therapy. Patients who failed to improve with this treatment, with significant ongoing symptoms of pain and stiffness, were offered arthroscopic capsular release with a manipulation.
Surgical Technique
Arthroscopic capsular release was performed in the beach
chair position as a day case procedure under general anaesthesia
supplemented by an interscalene regional nerve block. The
operations were carried out by either of two fellowship trained
shoulder surgeons in the department (ASC & GCH).
Capsular release was performed using a radio-frequency
hook (3.0-mm 90° hooked electrode, Depuy Mitek, Raynham, MA)
through an anterior arthroscopy portal with a standard posterior
portal used for visualization. Release of the rotator interval, the middle glenohumeral ligament and the anterior capsule between
the 2 and 5 O’clock positions was performed under direct vision
with arthroscopic scissors used to complete the anterior capsule
release between 5 and 6 O’clock. The subscapularis tendon was
not released or violated. Arthroscopic release was followed
by gentle manipulation of the shoulder using a short lever arm
technique to achieve maximal range of movement.
During the study period it became routine practice to
perform an intra-articular injection of corticosteroid and local
anaesthetic (8ml 0.5% bupivacaine hydrochloride and 80mg
methylprednisolone) to the glenohumeral joint. Post-operatively
the shoulder was rested in a sling with instructions to remove it
once the effect of the interscalene block had ceased in order to
initiate early mobilisation.
Patients were seen by a physiotherapist before discharge
and given both verbal and written instructions about shoulder
exercises. Formal sessions were introduced at two weeks post
operatively as per protocol. Patients were followed up in the
outpatient clinic at regular intervals until suitable for discharge
[31-39].
Data Collection
Patient demographic and comorbidity details were
recorded with most Oxford Shoulder Scores (OSS) collected
preoperatively. Careful record was made of operative details
and any postoperative complications. All patients were followed
in the outpatient clinic until discharge. As part of routine
postoperative follow-up, patients completed an OSS after surgery
at each follow-up. A further OSS was obtained from patients by
postal questionnaire at a minimum of 1 year postoperatively.
Severity was based on interpretation from Dawson et al. [12] but
using the inverted range (0-48) with a greater score representing
fewer symptoms.
The last postal OSS was completed together with the
Southampton Shoulder Satisfaction Index. The Southampton
Shoulder Satisfaction Index contains two primary outcome
measures:
a. Overall satisfaction with the outcome of surgery
(Response: 10-point visual scale between 1 and 10, from
1 not satisfied to 10 highly satisfied)
b. Whether the patient would choose to have the operation
again (Response: Yes/No).
A. Secondary outcome measures included:
i. Time until improvement of shoulder symptoms
(Response: 12-point visual scale between 1 and 12
months)
ii. Return to work (Response: Yes/No)
iii. Whether the patient’s quality of sleep had improved
(Response: Yes/No)
Statistical Analysis
Paired t-tests were performed to compare pre- and postoperative OSS. Unpaired t-tests were performed to assess variation in OSS between different groups.
Results
Arthroscopic capsular release was performed on 135
shoulders in 132 patients with primary frozen shoulder but a
certain number had suspicion of a concomitant impingement
syndrome. After postal and telephone reminders, a questionnaire
response rate of 88% (119/135) was achieved with the remaining
16 patients lost to long-term follow-up.
In 17% (20/119), subacromial decompression was also
performed at the time of surgery excluding them from further
statistical analysis thus leaving 99 pa
tients suitable for inclusion
in the study.
51.5% of this cohort (51/99) received a peri-operative intraarticular
injection. The demographic characteristics of these subgroups
were similar to that of the overall cohort.
The mean age of patient was 53 years (range 37 to 70 years)
with 53 men and 46 women, of whom 20% (20/99) were diabetic
and 53 were right sided operations. Mean follow-up was 28
months (range 4-88 months) with 76% (75/99) having followup
greater than 12 months.
Complications were seen in 11 of our 99 patients (11%).
6 patients had ongoing pain at final follow-up, two described
weakness, two described stiffness, one had recurrence and
one had a possible ophthalmic artery infarct, not thought to be
directly related to this surgery.
Pre-operative OSS was available for 77 of the 99 (Subgroup 1),
but only 37% (37/99) had an early post-operative OSS recorded,
described as scores recorded within 6 months of surgery
(Subgroup 2). Thus, 2 sub-groups were identified for analysis
from the overall cohort and their demographics are shown in
(Table 1).
Oxford Shoulder Scores
In the 99 patients with long-term follow-up (mean 28
months) the mean postoperative OSS was 42 (median 46, range
4-48). 35% (35/99) had a postoperative OSS of 48/48, indicating
normal shoulder function. 64% (63/99) had an OSS of 44 or How to cite this article: RK Ray, A Patel, G Cox, A Cole. Patient Satisfaction and Patient Reported Outcome Measure Data in Arthroscopic Release of
Frozen Shoulder. Orthop Rheumatol Open Access J. 2015;1(1): 555553. 004
greater, indicating near normal shoulder function. 32% (32/99)
had persistent mild to moderate symptoms (OSS 24-43) and only
4% (4/99) had persistent severe symptoms (OSS under 24).
In the 77 patients with pre-operative and post-operative
OSS (after greater than a year) a highly clinically and statistically
significant improvement in OSS was seen. Mean pre-operative
OSS was 23 (+/- 7.65SD), which improved to 44 (+/- 6.62SD)
post-operatively (p<0.0001, 95% CI -23.72 to -19.16)
In the 37 patients with pre-operative and both early and late
post-operative OSS, an early improvement in OSS was seen within
a mean post-operative period of 4 months which was sustained
and further improved at long term follow-up (mean 37 months).
This was statistically significant P<0.0001 (Table 2).
For further analysis the 77 patients were split into two groups
by the severity of their pre-operative OSS. A severe group (OSS ≤ 23) (n=38) and a mild to moderate group (OSS 24-43) (n=39).
When pre and postoperative OSS were compared, there was
a significant difference, suggesting a poorer, but still clinically
acceptable, outcome in the presence of more severe symptoms at
the time of surgery (Table 3).
Southampton Shoulder Satisfaction Index
The level of satisfaction was very high. Of the questionnaires
returned, mean satisfaction score was 9/10 (range 3-10)
with 43% (43/99) scoring 10/10. The mean time reported for
symptom improvement was 4 months (median 3, range 1-12).
88% (87/99) had returned to work, 92% (91/99) reported
an improvement in the quality of their sleep and 94% (93/99)
stated that they would have the procedure again.
Similar satisfaction levels were found in Subgroup 1 who had
pre-operative OSS recorded. Table 4 summarizes the results of
the satisfaction questionnaire.
Intra-articular injection
There was no statistical difference in post-operative OSS or satisfaction between those patients who received an intraarticular injection and those who did not (Table 4).
Diabetes
In these 99 patients there was no significant difference in post-operative OSS between diabetic (mean OSS 43) and nondiabetic patients (mean OSS 42) (p =0.6232). There also appeared to be no significant difference in the severity of symptoms preoperatively between diabetics (mean OSS 23) and non-diabetics (mean OSS 23) (p = 0.893). As a group, their responses to the satisfaction questionnaire questions appeared no different to the overall response (Table 4) and there was no trend for these patients to do worse than their non-diabetic contemporaries.
Discussion
Although some frozen shoulders may spontaneously resolve,
patients presenting to our specialist shoulder clinics are generally
frustrated with the longevity of their symptoms.
Our study demonstrates good relief of symptoms with
anterior capsule and an interval release with an MUA, reducing
the risk of axillary nerve or subscapularis tendon damage that
may ensue with a more extensive release.
We are able to establish that arthroscopic capsular release
for primary frozen shoulder gives significant improvement in
shoulder symptoms and function when assessed using a jointspecific
PROM such as the OSS and produces a very high level of
patient satisfaction. 94% of patients would have the procedure
again if required.
In our series, the patients in whom early post operative OSS
were available showed a significant early improvement in their
OSS with a further improvement at a mean of 30 months post
release to a near maximal OSS. These results show that most of
the improvement in symptoms occurs within the first few weeks
but further improvement occurs several years after the release.
This potential for early postoperative recovery is reinforced by the response to our patient questionnaire where the reported
median time for symptom improvement was 3 months. At a
recent discussion at the national meeting for shoulder surgeons,
early recovery was seen to be the main thrust for surgical
intervention and suggestions were made that we should be
scoring our patients as early as two weeks post-operatively.
Our complication rate was comparable to that noted in the
literature, with only a suspected ophthalmic artery infarct
appearing out of the ordinary, but clearly unrelated.
Same day discharge is preferred by most of our patients, and
the excellent postoperative pain relief achieved with interscalene
block together with concomitant oral analgesia encourages early
discharge from hospital.
Throughout the literature, varying comments are made
regarding outcomes in diabetics but we did not find a significant
difference for those suffering from diabetes mellitus. Their preoperative
& post-operative OSS, satisfaction and improvement
was similar to non-diabetics.
Long-term outcome studies of primary frozen shoulder have
reported poor outcome to be related to severity of symptoms
on initial presentation [2]. In our study a significantly worse
postoperative OSS was found in those patients with severe
pre-operative OSS (OSS ≤ 23) compared to those with mild to
moderate preoperative OSS (OSS 24 to 43). However there was
still a clinically acceptable improvement in patients with severe
pre-operative OSS with a very high satisfaction amongst all
groups.
Though some centers choose routinely to administer steroid
intra-operatively, others would suggest the risk of infection is
too great. We saw no infections in our cohort and believe that no
harm has come as a result of their use in this study, however the
data would suggest there was no gain either.
Conclusion
Very few complications were recorded in our series, which
concurs with most of the previously published reports.
Arthroscopic capsular release has been established as a
highly successful procedure. This study shows excellent results
in a large group of patients with the specific diagnosis of primary
frozen shoulder, treated with an arthroscopic release, as reported
by the patient rather than the clinician.
We have actively moved to offering our patients
questionnaires as early as two weeks post-operatively and look
forward to publishing further work on early recovery as reported
by the patient. Both short and long-term outcomes are clearly of
interest here.
Our operative technique is not only safe and reproducible but
also allows faster overall recovery from pain and restricted range
of movement, permitting this age group to return to their desired
activities and their work sooner.
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Table 1: overall cohort and their demographics.
Table 2: pre-operative and both early and late post-operative OSS.
Table 3: Severity of pre-operative OSS in 77 patients.
Table 4: The results of the satisfaction questionnaire.