Virtual Round Table: Shoulder Surgery

Panel talks about arthroplasty problems, solutions

[Round Table, Part II: Panel discusses issues in shoulder arthroplasty]

MODERATOR Douglas W. Jackson, MD Chief Medical Editor President, Memorial Surgical Group Medical Director, Memorial Medical Center’s Orthopaedic Research Institute Long Beach, California, USA Frederick Matsen III, MD Professor and Chairman of the Department of Orthopaedics and Sports Medicine University of Washington School of Medicine Seattle, Washington, USA Anthony Miniaci, MD Professor of Surgery Division of Orthopaedic Surgery University of Toronto Toronto, Ontario, Canada Charles Neer, MD Professor of Clinical Orthopaedic Surgery (emeritus) and Special Lecturer College of Physicians and Surgeons Columbia University New York, New York, USA Gerald Williams, MD Associate Professor, Chief, Shoulder and Elbow Service University of Pennsylvania Philadelphia, Pennsylvania, USA

Dr. Charles Neer has been an originator and teacher of several of the major advances over the past 50 years in shoulder surgery. In putting together this round table, I felt this was an opportunity for us to ask his thoughts and perspective on how we got to where we are today in shoulder surgery. This gave me a reason and the pleasure to make contact with him again.

I first visited Dr. Neer in 1971 and did so frequently over the next few years. I saw patients with him in his clinic, and observed and assisted in some of his shoulder surgeries. As a young orthopedic surgeon trying to understand the shoulder better and improve my surgical results, I found those visits educational and inspirational. In addition to his knowledge and understanding of the shoulder, I was also impressed with his meticulous attention to detail during surgery, and his patient care and involvement in monitoring his patients’ rehabilitation. It was something one had to observe to appreciate. I always went back to my clinic and operating room after my visits with Dr. Neer stimulated to apply the principles and discipline he brought to patient care.

To open this round table, I asked Dr. Neer this question: What did he feel were the major advances during his career in shoulder surgery.

Charles Neer, MD: Prior to 50 years ago there was no shoulder replacement arthroplasty and almost no knowledge about the types of destruction of the glenohumeral joint that required arthroplasty. In this short period of time we have general agreement on the design of the implant (nonconstrained and aimed at preserving normal anatomy), technique and indications. In osteoarthritis there is uneven wear and flattening of the joint surfaces, but the soft tissue is usually normal, making it ideal for shoulder arthroplasty. In rheumatoid arthritis there is a systemic disorder that affects soft tissue as well as bone and granulation erosion of the joint surfaces may strike unexpectedly. The key to optimum success is to do the arthroplasty before the bone and rotator cuff have been destroyed.

Other newly-understood entities requiring arthroplasty include avascular necrosis of the humeral head, arthritis of recurrent dislocations, cuff-tear arthropathy, arthritis of Erb’s plasy, and selected neoplasms. The outcome of shoulder arthroplasty varies with the pathoanatomy and it is a demanding procedure, but in general, the outcome is superior both in function and durability.

Classification and treatment of proximal humeral fractures

The 4-Segment Classification with the understanding of the pathoanatomy (soft tissue and bone) of these frequently occurring fractures has been a great advance. These lesions comprise approximately 5% of all fractures. About 80% are minimally displaced and for generations surgeons were taught to treat this type with skillful neglect because of the common misconception that the shoulder has more motion than it needs and these fractures only occur in old people who do not require a better shoulder.

We now recognize that they occur in patients of all ages, including epiphyseal injuries. The worst fracture-dislocations typically occur in the middle years of life (average age 55 years) and they can be extremely disabling. Minimally displaced fractures require surgeon supervision consisting of progressive exercises after the head and shaft move together. Displaced fractures may require closed reduction, open reduction or prosthetic replacement of the humeral head depending on their category. The 4-Segment Classification provides the terminology that makes it possible for surgeons all over the world to consider the same anatomical problem. Surgeons do not need to agree on treatment, but to make progress, must agree on the pathoanatomy under consideration. In the future, treatment may change as improvements are made, but the pathoanatomy will not change.

Impingement, cuff tears and biceps lesions (anterior acromioplasty)

Subacromial impingement has long been recognized and was once treated by radical acromionectomy or lateral acromionectomy. These procedures detached the deltoid muscle and caused serious problems. The finding in the anatomy laboratory in the 1960s that impingement occurs anteriorly, not laterally, beneath the anterior edge of the acromion, undersurface of the acromioclavicular joint, and coracoacromial arch (now referred to as the “supraspinatus outlet”) led to the development of anterior acromioplasty.

This procedure enlarges the supraspinatus outlet relieving impingement wear on the rotator cuff and biceps without weakening the deltoid muscle origin. If the cuff ruptures, a second type of impingement occurs caused by loss of the head depressing function of the rotator cuff. Repairing the cuff tear helps relieve this type of impingement. Anterior acromioplasty done at the time of cuff repair has greatly improved the outcome of repairing “impingement tears.” This type of tear is very frequent in general orthopedic practice, is typically seen in patients over 40 years of age (average age 56 years at the time of cuff repair) and, in contrast to traumatic cuff tears, often occurs with no history of injury.

Acquired multidirectional instability (inferior capsular shift)

The frequent occurrence of glenohumeral dislocations has been known since ancient times. Murals in Egyptian tombs depicted glenohumeral dislocations as early as 3000 B.C. In the late 5th century B.C. Hippocrates taught that some dislocations result from injuries (and are amenable to treatment with a red hot poker) while others occur in loose jointed individuals some of whom dislocate “at will.” Thus he recognized “traumatic” and “atraumatic” dislocations and that some are “voluntary.”

However, it is only during the last 25 years that “acquired instability” from repetitive microtrauma (repeated minor injury such as in swimming, throwing, gymnastics, etc.) has been recognized. This type of instability is often multidirectional and has been the leading cause of failure of standard surgical repairs for recurrent anterior dislocations. The patient may or may not recall an injury. The basic lesion is a redundant inferior capsular pouch and inferior instability and dislocation or subluxation occurs three ways (inferior, anterior and posterior). Surgical treatment is by inferior capsular shift, which tightens the capsule on all three sides, usually through one approach.

Jackson: Dr. Neer has succinctly highlighted the major advances in our understanding of the pathology encountered in shoulder surgery over the past 50 years. I have asked a panel of experts to comment on their current clinical approaches to this symptomatic shoulder pathology in their patients.

Dr. Williams, we all know Dr. Neer was a major contributor in the development of shoulder arthroplasty. How many shoulder arthroplasties are done in United States today?

Gerald Williams, MD: Approximately 18,000 to 20,000 shoulder replacements, both hemiarthroplasties and total shoulder arthroplasties, are done per year in the United States.

--- Arthrograms of a patient with continued pain following a total shoulder arthroplasty with an uncemented tapered monobloc stem. Both images show dye within the humeral canal, one in the metaphysis (left) and one in the shaft near the tip of the stem.
COURTESY OF GERALD WILLIAMS

Jackson: When arthroplasties are successful both the patient and physician are pleased. Please comment on those few patients that persist with or develop post shoulder replacement pain. What does a painful postoperative shoulder arthroplasty mean?

Williams: When shoulder replacement is performed for primary glenohumeral arthritis, good to excellent pain relief is obtained in more than 90% of cases. When pain persists following shoulder arthroplasty, there is almost always a reason. One must remain vigilant in attempting to identify the cause, as it may not be initially obvious.

Potential causes for persistent pain following shoulder arthroplasty can be divided into intrinsic and extrinsic conditions. Intrinsic causes include nonanatomic reconstruction, glenohumeral instability, rotator cuff tears (including subscapularis repair dehiscence), biceps tendon pathology, glenoid wear (both native and prosthetic), infection, aseptic loosening, and peripheral nerve injury. Extrinsic conditions include cervical radiculopathy, metastatic neoplasia, subacromial impingement (in the absence of a nonanatomic reconstruction), and acromioclavicular arthropathy. Infection should be considered in all cases of painful shoulder arthroplasty, even if another potential cause has been identified.

Jackson: How do you proceed in your evaluation?

Williams: Evaluation of the patient with persistent pain following shoulder arthroplasty must be thorough and should occur repeatedly until the cause is found. Diagnostic tools include a history, physical examination, plain radiography, CT scans, CT arthrogaphy, MRI, laboratory testing, electromyography, diagnostic injection, and diagnostic arthroscopy.

An adequate and thorough history and physical examination should be obtained. It is important to know whether a period of pain relief was attained following the arthroplasty before the pain returned. Wound healing problems should be noted and a history of any persistent drainage at the time of the primary surgery should be elicited. Physical examination should include an assessment of the wound and surrounding skin, passive and active motion, strength, and certain provocative signs.

Extreme stiffness may indicate an overstuffed joint, inadequate surgical contracture releases, or inadequate rehabilitation. Internal rotation weakness and a positive lift-off or abdominal compression test suggest subscapularis deficiency. If this is severe, it may be associated with an increase in external rotation and anterior subluxation. A positive impingement sign and biceps provocative sign may indicate subacromial impingement or biceps adhesions or subluxation.

Adequate plain radiographs may be difficult to obtain. Necessary views include an anteroposterior view in the scapular plane in both internal and external rotation and an axillary view. In order to see radiolucent lines around the glenoid on anteroposterior radiographs, scout fluoroscopic views or views taken with the shoulder abducted may be needed. Moreover, serial radiographs should be compared to identify change in implant position or any new radiolucencies around the components.

Jackson: If these preliminary screens do not give an answer, what comes next?

Williams: Specialized radiographic studies are not necessary in every case. However, if plain radiographs do not reveal the cause for persistent pain, CT arthrography or MRI may be useful. CT arthrography in the case of component loosening may reveal dye in the bone cement or bone-implant interface. MRI scanning using special sequences may reveal rotator cuff tears. Indium or gallium scans may be useful when loosening or infection are suspected.

Serologic testing is indicated in the evaluation of a painful shoulder arthroplasty, particularly when another potential cause for pain cannot be identified. Useful tests include a complete blood count with differential, erythrocyte sedimentation rate, and c-reactive protein. Although these tests are nonspecific, they can be a sensitive indicator of infection.

Diagnostic arthroscopy is reserved for cases in which no obvious cause has been confirmed but may be suspected. The most common causes of persistent pain identified by diagnostic arthroscopy include glenoid component loosening, biceps adhesions or subluxation, and rotator cuff tears.

In summary, persistent pain following shoulder arthroplasty for glenohumeral arthritis is uncommon and should prompt a thorough search for potential pathological causes. If one is diligent, the cause for persistent pain is almost always found.

References

• Bonutti PM, Hawkins RJ, Saddemi S. Arthroscopic assessment of glenoid component loosening after total shoulder arthroplasty. Arthroscopy: The Journal of Arthroscopic and Related Surgery, 9: 272-276, 1993.
• Boyd AD Jr, Aliabadi P, Thornhill, TS. Postoperative proximal migration in total shoulder arthroplasty. Incidence and Significance. J Arthroplasty, 6(1): 31-7, 1991.
• Cofield RH, Edgerton BC. Total shoulder arthroplasty: complications and revision surgery. Instr Course Lect, 39: 449-62, 1990.
• Freedman KB, Williams GR, Iannotti JP. Impingement syndrome following total shoulder arthroplasty and humeral hemiarthroplasty: treatment with arthroscopic acriomioplasty. Arthroscopy, 14(7): 665-70, 1998.
• Hersch JC, and Dines DM. Arthroscopy for failed shoulder arthroplasty. Arthroscopy 16(6): 606-12, 2000.
• Moeckel BH, Altchek DW, Warren RF, et al. Instability of the shoulder after arthroplasty. J Bone Joint Surg Am, 75(4):492-7, 1993.
• Sanchez-Sotelo J, O’Driscoll SW, Torchia ME, et al. Radiographic assessment of cemented humeral components in shoulder arthroplasty. J Shoulder Elbow Surg, 10(6):526-31, 2001.
• Sperling JW, Cofield RH, O’Driscoll SW, et al. Radiographic assessment of ingrowth total shoulder arthroplasty. J Shoulder Elbow Surg, 9(6): 507-13, 2000.
• Sperling JW, Potter HG, Craig EV, et al. Magnetic resonance imaging of painful shoulder arthroplasty. J Shoulder Elbow Surg, 11(4): 315-21, 2002.
• Wirth MA and Rockwood CA Jr. Complications of shoulder arthroplasty. Clin Orthop, (307): 47-69, 1994.

Jackson: Dr. Neer raised the importance of recognizing the direction of the instability. Dr. Miniaci, is there an agreed upon definition for multidirectional instability of the shoulder?

Anthony Miniaci, MD: Unfortunately, the definition of multidirectional shoulder instability is an elusive one. Many of the articles published now classify patients as having multidirectional instability whereas, in reality, the patients do not have true instability symptoms and therefore only have multidirectional laxity. In order to determine what appropriate treatments and results of treatments are for these patients, we need to have a good understanding of the definition of what the problem is. In order to achieve this, we need to define the patient population, symptoms and surgical pathology.

Patient population includes determining the type of instability (voluntary, involuntary, habitual), direction (anterior, posterior, multi), injury pattern (traumatic, atraumatic), and laxity (degree, generalized vs. focal, asymmetry).

Symptom definition needs to determine whether patients are complaining of pain, instability-subluxation/dislocation or both.

Surgical pathology can be varied and includes capsular laxity, labral or cuff pathology, Bankart lesion and bony defects. All of these factors go into the “definition” of the type of patient with MDI that you are dealing with and each variable will have an impact on the type of treatment that you choose and the results one can expect from that treatment for that individual.

Jackson: Dr. Miniaci, among the MDI surgical treatment options, what are some take away points for our readers?

Miniaci: As we have already discussed, depending on the definition of the patient that we are treating there are many different treatment options available. These include open inferior capsular shift, arthroscopic inferior capsular shift and interval closures, and thermal capsular modification.

Open inferior capsular shift is a traditional, humeral-based capsular shift. The surgeon must assure shift of the capsule is in the north-south plane, not east-west because east-west shifts result in loss of external rotation and potential recurrent instability. In addition, if only the superior portions of the capsule are tightened and the inferior capsule is left loose, this creates what I refer to as a flask deformity (based on the shape of an Erlenmayer flask) where the inferior pouch remains large and redundant. This creates a situation for potential recurrent instability in an inferior direction. These patients exhibit a loss of external rotation and have more trouble relocating their shoulder than before surgery once it dislocates again. The key to a good open capsular shift is a thorough capsular exposure and appropriate shift superiorly without causing a loss of external rotation.

The long-term surgical results of this type of treatment is generally best for MDI patients with true instability and generalized laxity. This must be approached from the front in most, but the surgeon may want to consider a posterior approach in those patients with MD laxity but posterior predominance of symptoms.

The same principles apply with the arthroscopic capsular shift as with the open shift except that technically, the capsular shift is based on the glenoid and not from the humerus and, therefore, the amount of capsular shift is often less. Many different approaches can be used to reduce the capsular volume, including capsular detachment and advance, or capsular tucks. Be careful with tucks because the tendency is to reduce capsular volumes in all directions, which can cause stiffness (loss of rotational motion) or failures. Interval closure is possible and considered important arthroscopically. This is sometimes combined with focal or minor thermal treatment. Overall, I find this type of treatment best for patients with laxity and/minor instability complaints with pain. It is possible to treat patients with MDI and true instability arthroscopically but adequate shift must be ensured. My approach to patients with MDI has been based on the following classification:

MDI with true dislocations/instability:

• Thermal capsular modification not very successful
• Open or arthroscopic shift preferred
• Beware of other pathology

With voluntary instability, especially posterior, an open procedure is still preferred.

MDI with no instability complaints but pain:

• Arthroscopic shift excellent
• Treat other pathology, often labral tears will give asymmetric laxity
• Thermal as an adjunct is questionable/no proof but good reports
• When laxity is symmetric and no other pathology is identifiable, consider thermal treatment.

Jackson: What has your experience been with thermal capsular modification?

Miniaci: Thermal energy is becoming increasingly popular, first with the use of a laser followed by the use of radiofrequency devices. The laser is more expensive and more dangerous to use and requires specialized training. The radiofrequency probes are less expensive and easier to use.

The indications for thermal capsular modification are not clear. Most reported series treat and report on patients with a mixed clinical picture. Also, there are very few guidelines for use, and many questions concerning the indications for use, length of immobilization, how to treat the capsule, location of application, and potential complications.

A recent study I was involved in included 19 patients with MDI with true instability. In the two-year follow-up, there were nine failures, five had stiffness with reduced rotational motion, four had potential axillary nerve irritation. And surgical revision revealed capsular deficiency in one-third of the failures. We did not have much success in treating patients with posterior dislocation or voluntary types of instability patterns. Better results were seen in anteroinferior instability, more subtle instability patterns (subluxation vs. dislocaton).

There are also many unknown issues that make me cautious with using thermal treatment, including questions about immobilization time. Some authors recommend prolonged immobilization to allow the capsule enough time to remodel. We are still unclear whether this will improve the failure rate or simply increase the stiffness rate. Another question that has arisen deals with the type of treatment to apply to the capsule. Most would agree that “painting the capsule” leaves little viable tissue and could result in capsular deficiencies. Current recommendations suggest less thermal treatment in the form of capsular stripes/dots vs. painting. Will this approach reduce capsular damage? Only time and further research will tell us.

We need more research to determine the technique and indications. We must be careful in patient selection (ie, degrees of instability), and we need classification of patients being treated to determine the optimal method of treatment.

References

• Altchek DW, Warren RF, Skyhar MJ and Ortiz G. T-plasty: a technique for treating multidirectional instability in the athlete. Orthop Trans, 13:569-561, 1989.
• Bigliani LU. Anterior and posterior capsular shift for multidirectional instability. Techniques Orthop, 3(4):36-45, 1989.
• Bigliani LU, Kurzweil PR, Schwartzbach CC, et al. Inferior capsular shift procedure for anterior inferior shoulder instability in athletes. Orthop. Trans, 13:560, 1989.
• Bigilani LU, Pollock RG, McIlveen SJ and Flatow EL. The inferior capsular shift procedure for multidirectional instability of the shoulder. American Orthopaedic Association, 106th Annual Meething, Coronado, Calif., June 1993.
• Cooper RA and Brems JJ. The inferior capsular shift procedure for multidirectional instability of the shoulder. J Bone and Joint Surg., 74-A:1516-1521.
• Cordasco FA, Pollock RG, Flatow EL and Bigliani LU. Management of multidirectional instability. Operative Techniques in Sports Medicine, 4:293-300, 1993.
• Endo H, TakigawaT, Takata K and Miyoshi S. A method of diagnosis and treatment for loose shoulder (in Japanese). Cent. Jpn. J. Orthop Surg. Traumat, 1971, 14:630-2.
• Harryman DT, Slides JA, Harris SL and Matsen FA. Laxity of the normal glenohumeral joint: a quantitative in vivo assessment. J. Shoulder and Elbow Surg. 1:66-76, 1992.
• Miniaci A, McBirnie JL. Thermal capsullorraphy in the treatment of multidirectional shoulder instability, a prosepctive consecutive series. (submitted publication JBJS)
• Neer CS II, Foster CR. Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder, a preliminary report. Journal Bone and Joint Surg. 62A:897-908, 1980.
• Neer CS II. Shoulder reconstructions. Saunders, Philadelphia, 1990:273-341.
• Norris TR and Bigliani LU. Analysis of failed repair for shoulder instability — a preliminary report. IN Bateman JE and Walsh RP. Eds: Surgery of the Shoulder. Decker, Philadelphia, 1984.
• Treacy SH, Savoie FH, Field LH. Arthroscopic treatment of multidirectional instability. J Shoulder Elbow Surg. 8:345-350, 1999.

Jackson: Dr. Matsen, a question that many physicians struggle with in caring for their patients is who should have a cuff repair and who should not?

Frederick Matsen III, MD: Rotator cuff lesions present in a wide variety of individuals, with a wide variety of symptoms, and in a wide variety of patterns. Before considering a surgical approach to a cuff tear, it is important to understand the functional deficits and expectations of the patient, the reparability of the cuff defect, and the factors that may affect the outcome.

In general, acute full thickness tears merit consideration for early repair before tendon resorption and muscle atrophy can occur. Chronic tears merit consideration for repair if there is evidence of good residual muscle and tendon. Symptoms from irreparable tears may respond to smoothing of the humeroscapular motion interface. In all cases we preserve the integrity of the coracoacromial arch.

Jackson: Dr. Matsen, what are your priorities in treating disorders of the rotator cuff?

Matsen: My priorities are:

Preserve the deltoid. Thus, surgical approaches are conducted through either the superior “deltoid-on” approach.

Assure smoothness of the humeroscapular motion interface. Thus, the upper aspect of the humerus and cuff must present a smooth convexity to articulate with the concave undersurface of the coracoacromial arch. All hypertrophic bursa and excrescences of the tuberosities are removed leaving a smooth proximal humeral convexity. Sutures are placed so that the knots do not lie on the superior aspect of the cuff or tuberosity.

Maintain the normal mobility of the glenohumeral joint. Thus, limiting scar must be resolved and the cuff tendons must be released from the glenoid and coracoid before reattachment.

Assure an even distribution of tension on the cuff insertion. Thus, differential tightness at the area of cuff repair is avoided.

Assure that if cuff tendon reattachment is performed, that it is sufficiently robust to heal and to allow early motion after surgery. Thus, multiple sutures securing the tendon edge into a bony trough are preferred. The trough excludes joint fluid from the repair site and allows for some slip of the tendon while maintaining tendon to bone contact.

Implement immediate postoperative continuous passive motion so that adhesions in the humeroscapular motion interface are avoided.